B.pharm

Candidate must have at least clear his/her class 12th with minimum 50% of marks in aggregate from higher senior secondary. All SC/ST candidate should have 5% of relaxation.

B. Pharmacy is better because many opportunities are present in the pharmacy field.

Yes, you can pursue B.Pharm in a good college. You need to score good marks in class 12th for the same.

Yes, you can pursue B.Pharm from a reputed college on the basis of your class 12th score.

It depends on the field of your interest. Microbiology will mainly deal with microorganisms and there interaction with the environment as well as the benefits we can garner from their engineering. Whereas, pharmacology will deal with all the medical aspects as well as chemistry of drugs.
If you are looking for job opportunities after completing this courses both will grantee a good one, provided you have a Masters degree in hand.
All the best.