Ramjas College is the best for M.SC maths in Delhi. But you should do a proper research according to your needs before selecting a college. A selection of college involves many other factors as well, you should not go ahead with a college only because of it's name if it is not meeting up with your needs.

Hey!

The list of some of the best colleges that offer M.Sc. Mathematics is mentioned below:

1. Ramjas College
2. Hansraj College
3. Manav Rachna University
4. Miranda House
5. Sri Venkateshwara College
6. Hindu College
7. Acharya Narendra Dev college
8. The Northcap University

Hope this answer helps!