For BSc and other such courses Delhi University is arguably the best institution. Every college of DU is almost well equipped for giving A grade knowledge and a classy college life but, I don't think 75% in 12th is going to get you a seat in any of the DU college unless you are from reserved category. Still you can apply and try your luck. 

Other best options for you are BHU and JNU where you have a genuine chance to get an admission by giving the entrance exam.