Science

Both are good branches. M.Sc in biochemistry will be better as you will be able to work in both medical and non-medical fields.

Hello Dear,
You are a B.Sc physics graduate, don't think that you don't have many options. The options are immense my dear, you can prepare for JAM, it is an entrance exam conducted by IITs for M.Sc. that will open the roads of success for you. if you are inclined towards management course then you can also do MBA in the similar field. If you want to go for civil services then you can prepare for that. All the very best for your future.

Can I know your class 12th percentage?

It's better to start commerce from 11th, but if you think science stream not interesting, you may choose commerce, but need a little bit hard work to keep update yourself with basics of commerce.

You can pursue it but why do you want to go for Diploma course. Go for an undergraduate course by studying in government colleges for 5 years with proper animal husbandry.

You have many career opportunities from environment engineer to conservatism of environment hazards / government jobs to private sector. In this global warming and polluting world, it's wise and a good choice.

It is very necessary to take maths for doing B.Com honors. Specifically if you want to go for some highly reputed colleges like SRCC, LSR, St. Xavier's and others I recommend you to take maths.

As per me, B.Sc in IT is a better option than B.Com.
Good luck.

The admissions are closed for the academic year 2017-2018 for B.Sc in physics.

According to your power of tolerance and power to survive, you can choose physics, next chemistry and then zoology.
You should go for either Central University (CUCET) or IISER or NISER (NEST).