Hello there! 

Greetings! 

You haven't mentioned what kind of colleges are you looking for like engineering or something else . 

You can get admissions in top colleges of DU with your class 12th marks. For Science Stream: St. Stephen is said to be the best college for science students. every year cutoffs go beyond 95%. You have to also give interview if you clear the cutoffs. Miranda House for Botany B.sc. 

You can even get admission in Engineering colleges on the basis of class 12 th marks . For example, Tamil Nadu Engineering Admissions aka TNEA – Conducted by Anna University, TNEA is as the name suggests based on the marks obtained in the qualifying exam i.e. 10+2. 

Also in Sastra University , admission is given  in two streams. In stream 1, B.Tech admissions will be on the basis of JEE Main 2018 and qualifying exam scores for 70% seats. In stream 2, B.Tech admissions will be on the basis of qualifying exam scores for remaining 30% seats.

For more information go through the link below :-
https://engineering.careers360.com/articles/btech-admissions-on-basis-of-class-12th

Thankyou