Class 12-science

Check out BSc courses. If there is any subject you are interested in, then take up its Bsc course. After Bsc, you can go for MSc. Other option is that you can go for BCom or BBA or BA now. Choose well.

One can pursue DMLT after 10th directly. For BMLT 10+2 is required. DMLT is a 2 year course and you can get admission in any of the good medical institutes offering the same. This course is available in AIIMS, Christian Medical College and many others.

The stream in 12th does not matter,The eligibility depends on the type of course that you wish to pursue , the details of some courses is stated below:
Diploma –Class 10th pass from a recognised board with minimum 40% marks.
Bachelor's Degree: Class 10+2 examination with at least 50% marks.
Post-graduation degree: Bachelor's degree from a recognised university with at least 45% marks.
Graduate & PG programs may also require you to appear in entrance exams such as NCHMCT,AIMA UGAT, E-CHAT etc.

Opting for Commerce is a good idea. But, in the same time, start working out on other aspects required for a Bank exam. It is highly competitive and hence, you can not ignore any aspect.

It is better to continue your 12th instead of doing diploma from the beginning. Already, you have a gap of two years and you should cover that gap. You can write a letter for gap in between your studies with a reason. After completing that you can proceed with further according to your plan for future.
All the best for your future. Take a wise decision and proceed.

Qualification for pharmacy is 12th with PCM or pcb