Hello Aspirant

After 12th mostly your admission are merit based(The marks that you score in your +2 grade).

Various colleges have various criteria,but this the basic criteria that you should get minimum 45-60% in 12th.But more good your percentage is the more chance is that you will get your desired college.

Not many colleges have entrance exam,but still you can ask the college committee if they conduct any entrance exam.

Regards!