In which college are you looking for? 

If it's for IIT then you have to acquire high rank in JEE Advance. 

If you want in NITs, IIITs across India then you must score above 250 marks in JEE Mains.

If you are looking for private institutes and colleges then you have to give the respective entrance exam conducted by that respective Institute and qualify in it. 

If you are looking for State government College then you have to give entrance exam conducted by that particular state.

If you still have any queries feel free to ask in the comment section down below.