Colleges in Kolkata

It depends on in which college you want to take admission.
If it is in Mumbai then 450+ score is required and for other colleges in Maharashtra, it is 400+ marks.

No, you don't have any chance of getting admission in Hi-Tech Medical College.

Dear Sharmistha,
You just need to give only one entrance exam (CAT) in order to get MBA at Amity University, Kolkata. You must have a valid percentage in CAT because you have low marks in class 12th.
If you have any query, ask me at anytime.
Good wishes.

You have a lot of options left with you as you have done you Masters. If you are very much interested in academics, then Ph.D is the obvious choice for you after completion of your M.Tech.
If not, then there are number of corporate giants that seek M.Tech pass outs as they want to hire subject matter experts. M.Tech makes you eligible for jobs in such big companies like google, Microsoft and more.

Your academic record is tad bit below average even for OBC category. I would suggest that you should give your best and score above 99 percentile or more to expect an admission call from IIM-A, B or C.

Hello Suman,
Please refer the link to get more insights of the colleges and branches:
https://www.shiksha.com/resources/college-comparison