Chemistry

Join NDA for that.

It is valid only if the institute you are currently studying and also the course is approved by UGC.

A job in a reputed pharmaceutical company is really a great opportunity nowadays and has some good pay range
But jobs in many private sector companies offer ridiculous pays for a Production/Quality control chemist.

If you want to join Ph.D. in research institutes of India, you have to clear entrance exam CSIR NET or GATE)
And, you have to go through a Personal Interview session.

Since you have completed M.Sc. Chemistry with 54%, you cannot improve your M.Sc. Marks which is fixed. But you can still improve your career by Understanding the basics of the theoretical part of Chemistry and lab skills.

To get admission in ICT Mumbai for MSc Chemistry, you should have passed BSc Chemistry and PCM in 12th grade. You should clear the entrance exam (GATE).

Yes, If you have developed lab skills. Good contact with professors about career planning in Industry can make some opportunities for personal contacts to some job offers.

No, Annamalai University distance education is not approved by UGC and deb.

Since you are interested in research, choose your specialization in M.Sc. Related to your research interest. Physical Chemistry is a Theoretical approach to Chemical reactions and properties. Organic Chemistry is about chemical reactions and properties of organic compounds
Both have a great scope at and after research.

Yes, If you are good at your lab skills and Strong understanding of the basics.