Hey,

If you get a seat in second round of all India Counselling and you do not join the college, then you can exit the all India counselling with forfeiture of security fees. But if you report to the allotted college in second round of counselling, then you cannot leave the seat and go to state counselling.

If you exit the second round counselling, then you have to register fresh during the mop up round of all India counselling if you want to participate in it.

If you get a seat in second round of state counselling, then you have to report to the allotted college and further agree to participate in further rounds.

To get a list of colleges in which you can get a MBBS/BDS seat, you can use NEET College Predictor https://medicine.careers360.com/neet-college-predictor?icn=QnA&ici=qna_answer