University of Mumbai [MU]

Take the average of all semester marks to date. That would give you a fair idea. CGPA won't be of much use here since the requirement stated is in terms of percentage.

You can't do a BA in 1 year and this not a legal way to get a degree. Yes, Institute of distance and open learning provides distance education mode. If you are looking for a one-year bachelor course then look for the foreign university as they offer a one-year bachelor degree. Although you shouldn't look for a one-year degree course foreign universities are the option you have. You can also look for below options also:-
1. Amity University
2. Annamalai University
3. Mewar University
4. Suresh Gyan Vihar University
5. JIMS
6. NMIMS
Regards

Mumbai University offers distance learning programmes. B.Sc Computer Science is also offered. But, as per me, if you go to pursue it now, you will have to complete the first two years too again in correspondence.
Also, try to enquire at IGNOU. They might have some provisions which might help you.
All the best.

Diploma in Tourism & Travel Management: Eligibility
Candidate must have passed the 10+2 or equivalent level examination with at least 50% (40% to 45% for reserved category candidates) of the marks at 10+2 or equivalent level from a recognized state or central board.

Candidate must have passed 10+2 from a recognized board to get eligible for the course.

I think it is quite low percentage to get admission there. But, if the seats remain vacant you may get admission there, which is very unlikely though.
All the best.