Dear sir,

First of all heartiest congratulations to your son for getting such a excellent marks. As per now counseling has not been started You can put your category as obc in counselling registation form but to claim a seat in your respective category you will have to give the necessary central OBC caste certificate at the counselling time in the college.

As this year AIIMS and jipmer exams is also taken by NTA NEET ,there are little chances to grab him a seat in mamc by category rank. If u belong to Delhi state then you might definitely get a seat in MAMC, DELHI through 85% state quota seats.

you can predict this year rank through this link

hope he get college of his choice

gud luck

best regards!!