Masters

Yes, you can. You will have to appear for this exam https://www.shiksha.com/exams/isi-admission-test

The minimum criterion of eligibility needed to be MET for pursuing the course is a Bachelor's degree in Science with Biology, Maths and Chemistry as main subjects. Rest, eligibility might differ from one institute to another.

Graduate Aptitude Test in Engineering GATE may be right platform for you. If you wants to pursue the PG degree (M.Tech/M.E) from a reputed IISc, IITs and NITs etc. Than you must have to appear in GATE-2020 exam. This gateway will not open the door of best higher educational opportunities, but can also provide you the job opportunities in government. PSUs.

Switching from biology to commerce is a bit uncommon thing. If you are really interested in corporate world or plan to have a startup, then go for it.

Hi Paramita,
As you are applying for distance, then yes you can go for distance. If you had said for regular one, as your marks are low, as there should be minimum 50%. But, as you are choosing distance, then whichever university you are choosing, if it is UGC recognized and you can fill the form either visiting the university or downloading from the website of that university.

Applications for admissions to various Under Graduate and Post Graduate courses for the academic year 2019-20 will be available from March 1st week onwards.
http://sjc.ac.in/admissions.html

The eligibility details are not mentioned on the official website. You can contact them directly for the information http://www.stannscollegehyd.com/contactus.htm