Punjab

Yes, if you have knowledge then you are definitely eligible for a job. And after completing your degree, with your knowledge, you can get a good job.
Good luck.

NCC would be helpful for Police. NSS is just for name sake. Also, Income Tax recruitment is done mostly through SSC Exam.

There are 4 all India seats for civilians.

Yes, it is necessary for you to give an entrance either its JAM or JEST because IISER offers integrated Ph.D. programme. Here is the link:
http://www.iisermohali.ac.in/home/front-page-articles/admissions-to-int-phd-program-august-2018
IISER, Pune has the best research faculty among IISER institutes. M

Yes, you can do this course abroad. You are eligible.
Good luck.

Yes, you are eligible for the same.
Good luck.

IHM Chennai. Should ofcourse be your first choice. They have a well trained set of faculty. A decent enough campus and facilities.

With this rank, you should try for physical counselling of NIT-Kurukshetra, NIT-Hamirpur, YMCA, DCRUST-Murthal and UIET-Kurukshetra.

It is available on their website and past rank records. Still, you may check with your marks in College finder sites like here in Shiksha.com.