Dear Gaurav, AIIMS had a correction window allotted for errors to be corrected that have been made in the Basic Registration process. That is the only chance to correct any errors in the application form. Once your basic registration is completed and accepted, what you fill in there, stays there. Unfortunately you cannot make any changes whatsoever in the application form. 

Hey Gaurav Goyal,

You can’t change now because the edit option dates were already closed on 11th February 2019 and the final status of all the application were already updated on 12th February 2019. Unfortunately, you can’t edit the application now. 

Hope for the best!