Dear aspirant

You have not mentioned the name of thr entrance exam . Although the counselling are more or less same for all entrances. If you accept and freeze your particular allotted seat that is a particular department of a particular college then you can't make further changes . Either you get admission or you withdraw your chances in this year and try again for next.

Whether you have to direct contact college or not depends upon the entrance exam . Naturally you have to go physically for document verification in respective college or counselling centre.

Next time be specific and we will be able to help you.

Best Wishes.