M.Sc

You would most probably have to complete your M.Sc before you can enroll in a PhD program.

Different universities have different eligibility criteria for their Ph.D program. Please check with the university for admission requirements in their Ph.D program. On an average, the minimum requirement is 60% or 6.00-6.75 CGPA in their M.Sc. program. Please refer to the link mentioned below for a list of colleges which offer Ph.D programs and use the filters on the page to navigate to a program of your choice:
https://www.shiksha.com/humanities-social-sciences/colleges/ph-d-colleges-india

Sorry to say, you are not eligible. You should have studied Physics and Mathematics as cognate subjects i.e. in all 3 or 4 years of your undergraduate program and secured above 50% to be eligible for Master's degree.

You must ask the college where you're applying. Email and ask them if it is mandatory for them. Even if they say IELTS is not important to them, the visa issuing Embassy might still require you to write IELTS.

Hello,
Indeed, Germany has decent colleges and as far as education is concerned Germany is a good country. But this highly depends on the university you are applying.