Hey There,

So there is no term called as the free seat I any colleges. To get into any college you must have a valid rank to get into that college. You need to check which exams score they accept. 

And there is another process called Direct Admission and Management Quota. According to govt rules, some of the seats of every college are reserved for Management Quota. To opt that seat you need to pay a lump sum of money to that college also known as a donation which is not included in the fees structure of that college. And by doing this they will consider your admission to there college.

All the best