CAB (Citizenship Amendment Bill) made for illegal migrants from Pakistan, Afghanistan, Bangladesh (Three Islamic countries).
Who is an illegal migrant: Anybody who came to India after 1971 from these countries.
To whom does this rule apply: Illegal migrants who entered India till 2014.
What does it say: If one came to India before 2014 and stayed in India for certain years, they can become India citizens.
How many years: For Hindu, Sikh, Christian, Jain, Buddhist and Parsi 5years. For Muslims 11years.
Why segregation based on religion? Because of persecution of minorities in Pakistan, Bangladesh, Afghanistan. Pakistan, Non-Muslim population fell from 23% to 3%. Bangladesh, Non-Muslim population fell from 22% to 8%. Afghanistan, I don't know. Because, religious minorities from these three countries don't have any other place to go except India.
NRC (National Register for Citizens) is aimed at moving illegal immigrants to detention camps or they are free to leave to there actual country. During NRC one(Everybody in India) needs to prove there citizenship.
This Bill is applicable only for illegal immigrants(It has got nothing to do with Indian Citizens), If somebody wants to come to India legally, they can come.