Dear RIYA, yes you can attend all the three round counselling without surrendering the college.
But, you have to tell the authority about this. Since you have got college in first round that means you are a higher ranker student, so if you are attending second round or any other round you have to inform the authorities about it. Generally they ask about this before starting the counseling session.
If you have got the college in first round and you wanted different college and you are geeting it in some other round counselling you can change it by taking admission in new college and then show the admission slip to the earlier college. They will refund your fees with some deduction.
All the best :)
Feel free to ask for any query
Hope this helps.