CAA (Constitution Amendment Act) seeks to amend the definition of illegal immigrants for Hindu, Sikh, Parsi, Buddhist and Christian immigrants (not Muslim immigrants) from Pakistan, Afghanistan and Bangladesh, who have lived in India without documentation.
The National Register of Citizens (NRC) is a register of all Indian citizens whose creation is mandated by The Citizenship Act 1955 as amended in 2003. It has been implemented for the state of Assam between 2013–2014.The government plans to implement it for the rest of India in 2021. According to the Citizenship Rules, 2003, the center can issue an order to prepare the NPR and create the NRC based on the data gathered in the National Population Register (NPR). The 2003 further states that the local officials would then decide if the person's name will be added to the NRC or not, thereby deciding his citizenship status. No new rules or laws are needed to conduct this exercise in the whole of India. Assam, being a border state with unique problems of illegal immigration, an NRC for the state was created in 1951 based on the 1951 census data. But it was not maintained afterwards. In 1983, the Illegal Migrants (Determination by Tribunal) Act was passed by the Parliament creating a separate tribunal process for identifying illegal migrants in Assam. The Supreme Court of India struck it down as unconstitutional in 2005, after which the Government of India agreed to update the Assam NRC.
Following unsatisfactory progress on the update process over a decade, the Supreme Court started directing and monitoring the process in 2013. The final updated NRC for Assam, published 31 August 2019, contained 31 million names out of 33 million population, leaving out 1.9 million applicants, in which just about half a million are Muslim. The 1.9 million residents who were not on the list, and were in danger of losing their citizenship. Many of those affected were Bengali Hindus, who constitute a major voter base for the BJP. After the completion of the Assam NRC exercise, BJP did not find the results, meeting its expectations. BJP believed that several legitimate citizens were excluded while illegal migrants were included. The register was created because "illegal migration from Bangladesh has long been a concern" in Assam. The Amendment of the 1955 Citizenship Act, in part, helps protect non-Muslims who are not in the register and face arrest or deportation.
The ruling government of Bharatiya Janata Party has promised to implement the NRC for all of India in its election manifesto and during its speeches while campaigning for the 2019 General Election. On 19 November 2019 Home minister Amit Shah, declared in the Rajya Sabha of the Indian parliament that the NRC will be implemented throughout the country.