Atma Ram Sanatan Dharma College, University of Delhi

Hi!
So both the colleges are good. You can take the following into consideration:
The faculty is very good and supportive. Classes are held regularly, unlike a lot of DU colleges where classes are disrupted during the election season. I studied economics as my GE for four semesters, and the professors from economics department were really good. Admin department is also very good. The societies are really good and active. We have one of the best Western Dance Society. The enactus team is also pretty good.
4. The placement cell does a really good job in terms of placements and internships that are offered through out the year.
5. There are some really cool spots that you can visit in your free time. (Lajpat Nagar Mkt, Hauz Khas Village, Diggin which is right across the college, Siri fort park. )
6. Reverie, Gargi's annual fest is again amongst one of the best fests of DU. Preparations start 22.5 months prior. If you decide to join you should definitely participate, it can be a great learning experience. Hope this helps!

B.Sc. (Hons.) Mathematics is difficult to get at DU. The following are the other options.
1. B.Sc (Prog.) Physical Science with Chemistry at Bhagini Nivedita College (W)
2. B.Sc (Hons.) Instrumentation at Bhaskaracharya College of Applied Sciences
3. B.Sc (Prog.) Physical Science with Chemistry at Deshbandhu Colleg
4. B.Sc Applied Physical Sciences with Industrial Chemistry at Rajdhani College
5. B.Sc (Hons.) Electronics at Shaheed Rajguru College of Applied Sciences for Women (W)
6. B.Sc (Prog.) Physical Science with Chemistry& B.Sc (Prog.) Physical Science with Electronics at Shyam Lal
College
7. B.Sc (Prog.) Physical Science with Chemistry at Swami Shardhanand College
8. B.Sc (Prog.) Physical Science with Chemistry at Zakir Husain Delhi College