Hello,

As per your question, i would tell that the seats remaining vacant after 1st two rounds are filled up in mop up round. There is no fixed seat in mop up round. It varies evrry year. 

But analysing last year's mop-up events, it can be predicted that the seats should be around 500 to 700 only having a idea which might vary as no of students to sea ratio. Because last year in mop-up round about 700 seats are included in both government and private institutions.

For exact details and informations please keep checking the official sites too. 

Good luck.