B.Com

It is a private university, so I don't think it would be a good idea. You should go for Delhi University if you get good percentage in your 12th exams otherwise there are many central universities as well.

If you want best experience while pursing B.Com then Delhi University is the best. You can apply in DU and there are many colleges in DU to select from.

You can go for accounting Diploma like Tally, O level, etc. as it will be helpful for you in your future and if you are interested in any other field then you can go for interior designing Diploma.

No, MBA program at IIT Kanpur is not open to non- engineering students.
There is also no provision of management quota, applications are selected for GD PI solely on the basis of CAT percentile.

Yes, there is an opportunity for you but if you have anything strong like your academic or any entrance exam percentile then there is an opportunity for you.

You can apply for colleges - Doon Business School, Amrita Business School, Bengal Institute Of Business Studies, PSG-Coimbatore. Check the below link for more colleges-
https://www.shiksha.com/colleges-accepting-cat-scores-range-60-to-70-percentile-article-11984-1
I would suggest you must try one more time for CAT, as you won't be getting any premiere B-School at this score. You can try one more time and score good percentile.

If you want to pursue MBA further then BBA is a better option and if you want to go completely in commerce sector and not in business then go for B.Com. There are many good colleges offering both the courses.

Scholarships are mostly given by universities to students who are academically very strong, have a good profile and/or can demonstrate financial need. You must visit various university websites and check the financial aid section.