Science

Yes, you can get admission in IIT Delhi, but it may somewhere struggling for CS branch.

You need a result in which you are passed with 70 percentage. But, you cannot get a admission if you failed in any subject. But, if you passed in supplementary exam then you get a result which shows that you are passed in all subject. Then, you are eligible if you scored more than 70 percentage.

It will be better if you go for a graduation related to Mathematics. Because it will eventually help you in your preparation for IIT JAM Mathematics.

Hi,
I understand that you want to learn more about BBA before stepping into it. I would rather say you can try coping out with the syllabus easily it would't be so difficult to understand or something that way. Many of my friends from Science stream have actually taken BBA and are happy with their decisions. It's easy not too complicated. B.Com is comparatively difficult as it has too much of Accountancy when compared to BBA. You have taken the right choice of studies and I believe their is no requirements as such to have bridge course on BBA. I hope this was helpful for you. All the best.

Although you are on Boundary, you will get the admission if you apply in the first round which is already begun now. Also, keep VIM Pune as option.
Best regards.

I will suggest you for GATE exam. If in this you score very good, then your chances of getting a seat in the college like IIT IIIT etc. will increase. Also, many institute may conduct their own exam or they take admission on the basis of your past academics. GATE exam is a common gateway. But, many institute announced their own admission procedure. Mostly college will take admission on the basis of your Masters. But in government you need to qualify one national exam or your academics should be so good that you can even apply direct.

Go through the link below for details:
https://www.shiksha.com/science/exams/cucet/question-papers.