What is a single citizenship? Is it useful in Indian scenario?

Indian Constitution provides for only single citizenship i.e. the Indian Citizenship.

All the citizens of India irrespective of the states in which they are born or reside enjoy the same rights i.e. Political and Civil rights of the citizenship. They cannot be discriminated on any factor except for a few cases like tribal areas and Jammu and Kashmir where there are few restrictions.

The motive behind ensuring single citizenship was to grant uniform rights for all the people and this had been useful in Indian scenario as prior to the independence, there was a lot of discrimination on the basis of caste, creed etc., so single citizenship ensured equality and brought everyone under one umbrella.