CBSE

The CBSE (Central Board of Secondary Education) has a "best of five" rule for calculating the aggregate marks of students in the 12th grade. According to this rule, students are required to take five subjects in the 12th grade, and the marks of the three best subjects are considered for calculating the aggregate marks. If you are in the 12th commerce stream with accounts, economics, business studies, English physical education, and IT, and you do not pass in accountancy, then it will not be included in the best of five subjects for calculating your aggregate marks. You will have to select the best three subjects from the remaining five subjects that you have passed. It's important to note that each college or university may have their own admission criteria and requirements, and it's always best to check with the institutions that you are interested in applying to before making a decision. Some institutions may not consider the best of five rule and consider only the marks in accountancy or any other subject. It's advisable for you to focus on the remaining subjects and score well in them.

Yes, you can.
BACHELOR OF COMMERCE in Ravenshaw University has become a partly self-financing course since last year. According to sources, few of the students get into the course through merit list. I guess it was somewhat 86 percent and above last year, and the rest of them get through self-financing, which means you have to pay a sum of money around 50k during admissions over and above what the merit category students would pay.
Of course, there is a fixed number of seats and hence there would be a cutoff. But with 75.6 percent there should not be any problem in getting into the course, through self-financing.
Still, you should also apply for other universities under SAMS to be on the safe side.