West Bengal

Dear Rimpa,
Below-mentioned link is for the colleges providing biotechnology in Kolkata. It could be based on ranking, fee structure and placements. You can compare between colleges and make the right choice of institute for you higher studies.
https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.shiksha.com/science/colleges/biotechnology-colleges-kolkata&ved=2ahUKEwj-suTIlMPiAhUKSX0KHU6pAPAQFjAAegQIAhAB&usg=AOvVaw1O0FAex5p69OzaA11vCQ8d

Dear Karuna,
If you have completed your 12th from ISC board, you can surely get a chance to pursue your higher studies in this college. The admissions to the same will be based on entrance exam, group discussion and personal interview. I wish you all the best for your future.

You can take admission in IGNOU. It's quite affordable and is a central university.

You can take admission in IGNOU, it's a central university and it's fabulous for B.Ed. You can visit their website in order to know about the criteria and running of examination.

Yes, you are eligible to take admission in this college.

Admissions are open, you can apply.
Link:
https://www.ishm.co.in/

Yes, with state quota you may get a seat in a medical college.

All colleges accept NIOS students and they are considered equivalent. NIOS has sent circular to every State Boards/Universities to instruct their schools and colleges to allow admissions on the basis of Marks Sheets and Certificates issued by NIOS. All schools/Universities have recognised NIOS certificates for admission purpose.

They should accept it as you have domicile certificate of West Bengal. So, I don't think it will create any problem.