If I want to participate in second round of counselling without releasing the first round allotted seat What should I do?

You have to report to the college allotted in first round and complete the joining formalities. you should opt for upgradation while filling forms in the college. this will enable you to  participate in 2nd round… if you get seat in 2nd round, seat is first round is released and it is allotted to some other student as per the rank. If you are not allotted seats in second round you retain the first counselling set. while filling choices, keep only higher choices during 2nd round.