CBSE 12th

You have not mentioned the state from where you wish to do B.Sc. However, the following colleges offer B.Sc. On the basis of merit (marks scored in class 12th).
1. Miranda House, Delhi
2. Hindu College, Delhi
3. St Stephen's College, Delhi
4. Kirori Mal College, Delhi
5. Loyola College, Chennai
6. Madras Christian College, Chennai
7. Hansraj College, Delhi
8. Department of Sciences, Christ University, Bengaluru
9. Stella Maris College, Chennai
10. Deen Dayal Upadhyaya College, New Delhi
11. Mithibai College, Mumbai
12. St Xavier's College, Mumbai
13. Goswami Ganesh Dutta Sanatan Dharma College, Chandigarh.

Sorry, but no. For the general category, the cut-off is too high. You can opt for the B.A. Programme there or if you are from SC/ST category, there is a good chance that you get admission.

You need to do the competitive level study.

Yes, you are fully eligible for this course. To apply for B.A you must be pass in class 12. There is no age limit to pursue your graduation. Some open universities which offer this course.
IGNOU
Utkal University
And many other open universities.

Yes, you can. Diploma is considered equivalent to 12th.

Take admission in a college and present them a self-declaration stating a promise to present Pass certificate before an agreed date. They will give you admission. But keep in mind that your candidature may be cancelled if you fail again.

Scholarship's criteria is only the rank and course. It wouldn't matter if you took a gap:
http://www.inspire-dst.gov.in/scholarship.html.

Yes, you can. Check this link to know more:
http://pharmacy.nmims.edu/docs/admission-information-handout-d-pharm-batch-2018.pdf

Hi. The minimum duration for B.Ed through distance education is two years, however, the maximum duration five years. Admission to the distance mode programme is merit-based. Candidates should have scored a minimum of 50% aggregate in the undergraduate programme in any discipline and 55% in postgraduate programme. So, you are eligible. Thanks!

Hi,
If you have maths in class 12th, you can get admission in NMIMs by NPAT. Or, if you don't have not maths. So, you can take UGAT. UGAT is conducted by all India management associations.
good luck!