CBSE 12th

No, because last year's BA (Hons) first cut-off list is 98.20%.
Even if you belong to SC or ST category, the minimum required percentage is 85.

If you are interested in accounts, take admission for B.Com and then enjoy your subject.
But, for this, you must clear your basic of accounting.

12th marks are not included in counselling for NITs but you should have scored the eligible scores in the board exam to get NITs.
The minimum marks to be obtained in board exams are 75%. It is applicable for JEE Advanced also but it is better to score at least 75%.

Choose a path based on your interest, both are pretty good.

Campus placements are mainly based on percentage scored in the current course. School result will not be counted. Also, it depends on the college as what %age placements are provided. Speak to college authorities about this. I would suggest you still appear for the campus placements - might get lucky if selected.

A student having art stream in 12th standard can pursue his further study in art, humanities, management, media, fashion, journalism and tourism field. You need to specify which field you wish to go for. Accordingly I can provide detailed information.

That is a very tricky question. Most top colleges cut offs are in mid-90%. So, you do not have the chance to get through in top colleges. But, for some courses DU cutoff's are less (not sure which subjects you are looking for).
Otherwise, there are many more options - JMI University is best, IPU is reasonably good.
Besides these, you can opt for private universities in Delhi NCR.