Ph.D

You can apply if your are in your final semester for Masters. Different colleges have different selection procedure for Ph.D. check for these admission requirements.

Yes, you can go ahead.

M.Phil gives you a glimpse of what research is, whereas, Ph.D is all about the research on a particular subject.

For a guaranteed job in India, most important is communication or you can say English and which can secure a successful career is, undoubtedly, maths.
Good wishes.

Not more than one year gap is tolerated anywhere in the industry. If you have 1 year gap then it is fine but 2 or more years are not valid and will lead to rejection.

It is a good college for Ph.D in CS. Best of luck for your future and do well.

It is a good choice for Ph.D in CS. I would suggest you to go for it. Best of luck.

Colleges abroad have very different requirements compared to India. Check weather Masters here is recognized in the other country, and also check whether the college you are trying for will accept your qualifications in India.