Hi ,
TIFR is one of the most reputed college.
in order to help you I provide you information about the admission process and eligibility.

Eligibity criteria:
Your past record, your one-page write-up as well as your letters of recommendation will be considered. In our past experience, "good marks" do not necessarily make for a good research student; all students who are motivated to learn research skills are encouraged to apply. BSc-qualified candidates in any branch of biology are welcomed.
The Ph.D./ Int. Ph.D. written test will also function as the written test for our M.Sc. program. The test will be held at centers all over India. The test consists of multiple-choice questions covering *basics only* in physics, chemistry, math, biology. There is no guide book and no syllabus. No special knowledge or preparation is required. Revise your basic that is all.
The Interview will be based on whatever your BSc background is in, or whatever area you are most interested or most comfortable in.

Application process:
now for the application process you need to go through the TIFR site and apply the form online. They have a link where you can apply for the subjects you are interested in .

As far as the fees is concerned the fees per year is around 4000 to 7000 for a program depends on the course you chose .

I hope I was helpful
All the best