Dear Sachin, by selecting OBC category in NEET PG application form, you are declaring yourself worthy of Reservation. Because NTA doesn't know each candidates up and personal, they consider all the data entered to be correct and prepare only one merit list accordingly. Now on the day of counselling, if you do not produce the proof of your Reservation, the authorities don't have a back up merit list that they can consider you in the General Category. Your admission stands cancelled and you may be held for fraud and malpractise.