Hey Satakshi!

Any college of University of Delhi will have the exact same syllabus as the other for any course, in this case BA political science honours. Both, Gargi College and Kamla Nehru College have excellent faculty so academically there is no difference.
However, Gargi College is more recognized and preferred than Kamla Nehru College even their societies are really good so I'd say go for Gargi College.

Hope this helps!