Percentage in 12th class varies college to college

Can you please specify the name of the college or entrance exam?

n order to be eligible for IITs/NITs/IIITs and GFTIs you should have 75% marks in your boards exam or you should be in top 20 percentile. 

For SC/ST it is 65% marks. 

To know in detail about each entrance exam you can refer below link

List of Engineering exams

Good Luck!!