How is citizenship acquired in India?
In India, citizenship is regulated by the Citizenship Act, 1955. The Act specifies that citizenship may be acquired in India through five methods – by birth in India, by descent, through registration, by naturalisation (extended residence in India), and by incorporation of territory into India. 
Can illegal migrants acquire citizenship?
An illegal migrant is prohibited from acquiring Indian citizenship. An illegal immigrant is a foreigner who either enters India illegally, i.e., without valid travel documents, like a visa and passport, or enters India legally, but stays beyond the time period permitted in their travel documents. An illegal migrant can be prosecuted in India, and deported or imprisoned.
In September 2015 and July 2016, the central government exempted certain groups of illegal migrants from being imprisoned or deported.  These are illegal migrants who came into India from Afghanistan, Bangladesh, or Pakistan on or before December 31, 2014, and belong to the Hindu, Sikh, Buddhist, Jain, Parsi, or Christian religious communities.
How does the Bill seek to change the criteria for determining citizenship?
The Bill proposes that the specified class of illegal migrants from the three countries will not be treated as illegal migrants, making them eligible for citizenship. On acquiring citizenship, such migrants shall be deemed to be Indian citizens from the date of their entry into India and all legal proceedings regarding their status as illegal migrants or their citizenship will be closed.
The Act allows a person to apply for citizenship by naturalisation, if the person meets certain qualifications. One of the qualifications is that the person must have resided in India or been in central government service for the last 12 months and at least 11 years of the preceding 14 years. For the specified class of illegal migrants, the number of years of residency has been relaxed from 11 years to five years.
Are the provisions of the Bill applicable across the country?
The Bill clarifies that the proposed amendments on citizenship to the specified class of illegal migrants will not apply to certain areas. These are: (i) the tribal areas of Assam, Meghalaya, Mizoram, and Tripura, as included in the Sixth Schedule to the Constitution, and (ii) the states regulated by the “Inner Line” permit under the Bengal Eastern Frontier Regulations 1873. These Sixth Schedule tribal areas include Karbi Anglong (in Assam), Garo Hills (in Meghalaya), Chakma District (in Mizoram), and Tripura Tribal Areas District. Further, the Inner Line Permit regulates visit of all persons, including Indian citizens, to Arunachal Pradesh, Mizoram, and Nagaland.
Is the differentiation among the specified class of illegal migrants and all other illegal migrants reasonable?
The Bill makes only certain illegal migrants eligible for citizenship. These are persons belonging to the six specified religious communities, from the three specified countries, who entered India on or before December 31, 2014, and do not reside in the Sixth Schedule areas or in the states regulated by the Inner Line Permit states. This implies that all other illegal migrants will not be able to claim the benefit of citizenship conferred by the Bill, and may continue to be prosecuted as illegal migrants. Any provision which distinguishes between two groups may violate the standard of equality guaranteed under Article 14 of the Constitution, unless one can show a reasonable rationale for doing so.  The Bill provides differential treatment to illegal migrants on the basis of (a) their country of origin, (b) religion, (c) date of entry into India, and (d) place of residence in India. The question is whether these factors serve a reasonable purpose to justify the differential treatment. We examine this below.
The Bill classifies migrants based on their country of origin to include only Afghanistan, Pakistan and Bangladesh. While the Statement of Objects and Reasons (SoR) in the Bill reasons that millions of citizens of undivided India were living in Pakistan and Bangladesh, no reason has been provided to explain the inclusion of Afghanistan. The SoR also states that these countries have a state religion, which has resulted in religious persecution of minority groups. However, there are other countries which may fit this qualification. For instance, two of India’s neighboring countries, Sri Lanka (Buddhist state religion)  and Myanmar (primacy to Buddhism) , have had a history of persecution of Tamil Eelams (a linguistic minority in Sri Lanka), and the Rohingya Muslims, respectively. , , 
Further, there are other religious minorities from Pakistan, Afghanistan and Bangladesh, such as the Ahmadiyya Muslims in Pakistan (considered non-Muslims in that country) , and atheists in Bangladesh  who have faced religious persecution and may have illegally migrated to India. Given that the objective of the Bill is to provide citizenship to migrants escaping from religious persecution, it is not clear why illegal migrants belonging to other neighbouring countries, or belonging to religious minorities from these three specified countries, have been excluded from the Bill.
The Bill also creates further differentiation between the specified class of illegal migrants based on when they entered India (before or after December 31, 2014), and where they live in India (provisions not applicable to Sixth Schedule and Inner Line Permit areas). However, the reasons provided to explain the distinction is unclear. Note that certain restrictions apply to persons (both citizens and foreigners) in the Sixth Schedule areas and in the states regulated by the Inner Line Permit. Once an illegal migrant residing in these areas acquires citizenship, he would be subject to the same restrictions in these areas, as are applicable to other Indian citizens. Therefore, it is unclear why the Bill excludes illegal migrants residing in these areas.
How does the Bill change the regulations for Overseas Citizens of India?
The Bill also amends the provisions on registration of Overseas Citizens of India (OCI). OCI cardholders are foreigners who are persons of Indian origin. For example, they may have been former Indian citizens, or children of current Indian citizens. An OCI enjoys benefits such as the right to travel to India without a visa, or to work and study here. At present, the government may cancel a person’s OCI registration on various grounds specified in the Act. In case of a cancellation, an OCI residing in India may be required to leave the country. The Bill adds another ground for cancelling OCI registration — violation of any law notified by the central government.
This raises two issues. One, the Bill does not provide any guidance on the nature of laws which the central government may notify. The Supreme Court has noted that this guidance is necessary to set limits on the authority’s powers and to avoid any arbitrariness in exercise of powers.  Therefore, the powers given to the government under the Bill may go beyond the permissible limits of valid delegation. Second, the Bill delegates the power to notify laws and not offences. This may result in the cancellation of OCI for minor violations. For instance, the government may want to cancel the registration of an OCI who is found guilty of sedition, under the Indian Penal Code, 1861. However, since the government cannot notify one offence, it will need to notify the entire Indian Penal Code, which would include minor offences such as rash and negligent driving.
- . Section 2(1)(b) of the Citizenship Act, 1955.
- . State of West Bengal vs Anwar Ali Sarkar, AIR 1952 SC 75.
- . State of West Bengal vs Anwar Ali Sarkar, AIR 1952 SC 75.
- . Article 9 of the Constitution of the Democratic Socialist Republic of Sri Lanka states: “The Republic of Sri Lanka shall give to Buddhism the foremost place and accordingly it shall be the duty of the State to protect and foster the Buddha Sasana, while assuring to all religions the rights granted by Articles 10 and 14(1)(e).”
- . Articles 361 and 362 of the Constitution of the Republic of the Union of Myanmar state the following. “361. The Union recognizes special position of Buddhism as the faith professed by the great majority of the citizens of the Union. 362. The Union also recognizes Christianity, Islam, Hinduism and Animism as the religions existing in the Union at the day of the coming into operation of this Constitution.”
- . It is estimated that there are over a lakh Sri Lankan refugees in India, two-thirds of them in government camps. See https://timesofindia.indiatimes.com/city/chennai/why-lankan-refugees-are-reluctant-to-go-back-home/articleshow/65591130.cms
- . “Myanmar Rohingya: What you need to know about the crisis”, BBC News, April 24, 2018, https://www.bbc.com/news/world-asia-41566561.
- . “Why India is refusing refuge to Rohingyas”, Times of India, September 6, 2017, https://timesofindia.indiatimes.com/india/why-india-is-refusing-refuge-to-rohingyas/articleshow/60386974.cms.
- . The Second Amendment to the Constitution of Pakistan passed in 1974 effectively declared Ahmaddiyas as non-Muslims.
- . For example, see https://www.theguardian.com/world/2016/jun/11/bangladesh-murders-bloggers-foreigners-religion.
- . Hamdard Dawakhana and Anr., v. The Union of India (UOI) and Ors., AIR1960SC554; Confederation of Indian Alcoholic Beverage Companies and Ors. vs. The State of Bihar and Ors., 2016(4) PLJR369.
- Via PRS Explainer: The Citizenship (Amendment) Bill, 2019