After the third round a mopup round will be organised if some seats are still left which almost always happen. This is an offline counseling and you’ll need to go to AIIMS DELHI with your original certificates as 10th marksheet cum passing certificate, 12th marksheet, 12th passing certificate, migration certificate,etc.
There you’ll have to mark your attendance and then seats will be alotted according to your ranks. If you get a seat there will be a table of the respective AIIMS and they’ll help in your admissions.