Shaheed Bhagat Singh Evening College

Hello Prashant,
The very fact that you are talking about your desires and aims is a sign that you are bound to achieve your target. Every college provides opportunities to students to excel in extra curricular activities. It's up to you to grab the opportunity to come out of your she'll and shine in your desired field.
Best wishes.

Actually, the degree which is printed by Delhi University does not have the name of the college in which you had pursued your whole graduation. There is no impact of evening shift. You must perform well in your academics and other activities.

Yes, based upon your %, there are chances of getting admission but I suggest you to keep a watch on the cut offs released by the official University of Delhi's website i.e. www.du.ac.in.

BHU's main campus is what you should choose. It is the best college for maths Honors. No doubt, Shaheed Bhagat Singh college is also a very good college but still, BHU is better than it.

Unfortunately, getting admission in SBSC under general category with 51% marks is rather difficult and improbable.
The cut off generally ends at around 90% for the above course, which is way higher than your percentage.

Please refer the link for details:
https://www.shiksha.com/humanities-social-sciences/political-science/course/b-a-hons-in-political-science-shaheed-bhagat-singh-evening-college-sheikh-sarai-delhi-53660

Sri Venkateswara College has got better faculty for humanities courses, rather than Shaheed Baghat Singh College. But, if you have scored 86% chances of getting into Venky are slightly low, still you can try, as it depends solely on cut offs. All the best.

Yes, it is a mediocre colleges of Delhi University. You may go there. It has a good faculty and exposure.