Mark Zuckerberg and co. says the firm has started asking these details to limited users as a part of a small test. Not all the users will see such a prompt while creating a new account. Also mentioned is that although the prompt asks for users to feed their named based on the Aadhaar card, it is not necessary for them to do so.
"We want to make sure people can use the names they're known by on Facebook, and can easily connect with friends and family. This is a small test where we provide additional language when people sign up for an account to say that using the name on their Aadhaar card makes it easier for friends to recognize them. This is an optional prompt which we are testing, people are not required to enter the name on their Aadhaar card," said Facebook spokesperson to GadgetsNow in an emailed statement.