Hey Shubham! 

You have low chances for making into Delhi University. But, you can try for state Universities and some of them are really good. Secondly, try to pursue something along with your college, so you can compensate for your low score in twelfth grade. It could be also an an extra-curricular exam. So, best wishes for your future ahead. 

Hii

 The basic eligibility criterion for pursuing B.Sc. (Hons.) Mathematics degree is qualifying 10+2 or equivalent examination in Science stream with a minimum of 50% marks secured in Mathematics subject and/or in aggregate from a recognized board of the country.

If you satisfy the above eligibilty criteria, you can apply.

All the best.