Hey Vishal,

Yes the bank details have to be filled by all applicants in case of fee refund. For instance  if you take admission in a particular college in your first cut then you would be required to pay the fees of that college once you take the admission. But in the second cutoff you got a better college and decides to change then you'll get an option to get the refund. The fees will be refunded to your account once you withdraw your admission from that particular college.

Hope this is clear, ask if you still have query.