JEST

Definitely you will get M.Sc. Physics. The general eligibility criteria of most of the colleges is given below. Eligibility criteria : The candidate must have passed 10+2 or equivalent examination by a recognised board and B.Sc. Physics with 50% or above marks in aggregate. The candidate must have passed B.Sc. (General/Programme/B.Sc. (Pass) B.Sc. (H) Electronic, B.A. /B.Sc. (H) Instrumentation B.A. / B.Sc. (H) Electronics with 50% or above marks in aggregate. Further candidates appearing in their last semester of papers can also apply. Hence if you are writing the final exam of Bachelor degree than you are eligible for M.Sc. Physics.

Yes, you may eligible to apply for JEST exam.

Yes you can apply. For more details please visit https://www.jest.org.in/eligibility and respective participating institutes website.

Hello,
You can apply for both the exam if you fulfill the eligibility criteria for both the exams. Make sure that all the educational criteria you have for both exams. Both IIT JAM and JEST are held for the same purpose however there are some differences between them. There is no age limit for IIT JAM exam. The JEST is a screening test held for the selection of candidates for M.Sc, and Integrated courses on the other hand qualifying the IIT JAM exam will make you eligible to take admission into IIT institutes for M.Sc, Ph.D or other integrated courses. Hope it will help you.

Here you go to know all the detail about JEST
https://www.shiksha.com/science/jest-exam.