Economics

After your graduation, you can definitely go for PG in Economics. You can go for regular or distance PG in Economics. The most important thing is to keep your scorecard in graduation excellent. It will always keep you ahead of others. If Delhi is the criteria then just walk-in yourself into the campus of various colleges and try to find out which one is better. I personally believe that you are the best judge for yourself. I hope this would suffice. All the best and god bless you.

Normally, it has been observed that it can be done. However, at times in certain states, it is not allowed. You need to check with the nearby government college.
I hope this would suffice. All the best and god bless you.

Yes, you need to study mathematics as a subject in BA in economics.

MBA from any university. MBA in Entrepreneurship will be a real benefit for you as it will mould to be a good entrepreneur.