Hello dear aspirant

Hope you’re doing well

Usually colleges and universities provide float or freeze option in counselling rounds.
float means you’ve blocked your seat and can change it and are willing to participate in further rounds

Freeze means you block your seat and accept the college and don’t want to change seats in future.

Please check if this option is provided to you.

Also you need to pay the fees, but if you change college under that university only that fees get transferred to new college.

Hope this helps

Please ask if you have any more questions, you can write them in comments section.

Thanks