Ph.D

Check this link:
https://www.shiksha.com/ph-d-chp

May or may not. It depends on the college whether there is a direct admission or entrance exam for admission. All the best for your future.

Ph.D takes 3-5 years duration to complete the research that includes course work plus thesis. All the best for your future.

First of all, find your interested topics of your field then search which topic is currently in hot category and have supervisor available. Choose that topic for research. All the best for your future.

Job options
Jobs directly related to your degree include:
Acoustic consultant
Actuarial analyst
Actuary
Chartered accountant
Chartered certified accountant
Data analyst
Data scientist
Investment analyst
Research scientist (Maths)
Secondary school teacher
Software engineer
Statistician.

Hi Sushant
Of course you are eligible to do IIT JAM M.Sc. And Ph.D. Dual course with these subjects in your 12th standard so you should give the exam for the same. Good luck.

Students who are without a Master's degree will generally be admitted to the Integrated. D. Programme. Subject to completion of the necessary requirements, they will obtain an M.Sc. Degree mathematics, the study for which is to be completed within the first two years of their Ph. D. programme.

Yes, you can do MA, after B.Sc and after MA. You can do Ph.D as well. All the best.