Dual

Yes, you are eligible after passing OUCET exam. After completion of your PG, you can go for PhD as well.

Dear Harpreet,
I would suggest you to once check out with IGNOU. It is a well established brand name in distance education. The study material of IGNOU is of international standards and is industry ready. You may find some good combination of dual specialisation at IGNOU. I hope this would help. All the best and God bless you.

I'm assuming that you wanted to write about JEST (Joint Entrance screening test) and the answer is Yes, you can give JEST after B.Sc. To get integrated Ph.D. in many institutes you can check that on the site of JEST also there is integrated PhD. in TIFR where you've to give their own entrance exam GS also both of these entrance exams will be followed up by an interview. So best of luck and you actually should have potential to pursue for an integrated course.

BBA LL.B. Is a five year Integrated course. An aspirant will become a graduate in management as well as graduate in law after completing this course. Many companies hire those persons who complete this course. There are several colleges in India offering the course, National Academy of Legal Studies and Research University, HyderabadGujarat National Law University, Gandhinagar, GujaratNational Law School of India University, BangaloreSymbiosis Law School, NoidaIndian Law Institute, New DelhiGovernment Law College, Mumbai
For course details and placement related information, one may visit respective websites!

Go through the UGC approved university list on their official website and search for Seacom Skills University for all the details:
https://www.ugc.ac.in/privateuniversitylist.aspx?id=35&Unitype=3.

Hi Ramesh Pal,
Kindly mention your preferred location:
https://www.shiksha.com/bba/articles/integrated-mba-programmes-in-india-blogId-15044
https://www.shiksha.com/business-management-studies/articles/your-career-after-doing-an-integrated-bba-mba-blogId-4539

Yes, of course you'll be eligible to do that. You just need a Bachelor's degree for UPSC. Be it a 4 year programme or 5 years.

As you have just prepared for it, so don't worry, everything is going to be fine.
Good luck.

Well, you should definitely opt for Thapar. Thapar University is one of the best you get.
They have scholarships too making it great for students from abroad to get a quality education and hone their skills. It has been rated amongst the top-ranked innovation-driven private institutions and technical institutes in the country, Thapar Institute of Engineering & Technology has been accredited with an 'A' grade by the National Assessment and Accreditation Council (NAAC).

There is nothing like required score. As it is rank based, on your merit in comparison to other applicants. Higher you score, better the chance. Though, there exist some reservations too.