First, you have to complete your 1st year and clear all subjects, after that you can change the college and start your 2nd year in the new college.

Make sure to take the transfer certificate from your current college and submit it to the new college.

If you want to leave after your 1st year, then cancel your admission from your current college. Lastly, cancel your university PNR number and take the new PNR number, to get admission easily.