Hi.
Mop up round is a round or a list basically that comes out after all the rounds are done.
It is for filling all the vacant seats that have been left out after the rounds. Sometimes students leave their seats due to some reasons and the seats become vacant. The state council gives the students a date up to which the students can leave their seat without paying a fine. So the seats that remain empty are allotted to students. There are very few seats like that. So it’s basically a round to wind up all the seats and finish the counselling. Once you are allotted a seat in mop up round, you can’t leave it. You have to take admission in it.
I hope it helps
Good luck. For now you just study, rest all will be done.