There are two cases, first one is you are allotted a seat in a college in round 1 and you have accepted the seat but want to upgrade your seat you need to fill new choices for round 2. If you are allotted a seat in round 2 the seat allotted to you in round 1 will be cancelled.second case if you have not joined in the college which was previously allotted in round 1 and used free exit option even then your seat will not be retained.Either ways you will loose the seat which was allotted in round 1.If you are not allotted seat in round 2 then your seat will be retained which was allotted in round 1 if you have already joined.

(javascript%3A;)