Jaipur

I would suggest you complete your 12th first and then opt for a college. That will not only help in a better career but will also open various avenues for you in future. For the list of colleges, kindly refer to the link below:
https://goo.gl/9cro5n.

Nirma University have great faculty members, faculty student ratio is too good, great placement cell is USP of Nirma University. Just be in top 10 students in Nirma University and you will get good placement, Manipal University Jaipur is below par, just go for Nirma University.

It depends on your skills and experience. However, around 5 to 6 Lacs per annum you will get after completing your B.Tech + M.Tech in nanotechnology.

Yes, STIA Jaipur is fully government approved college of Rajasthan.

Check out the reviews below and filter stream to know the best branch :
https://www.shiksha.com/college/swami-keshvanand-institute-of-technology-management-and-gramothan-Jaipur-23158/reviews.

Well, MBM would be a better option.
MBM, Jodhpur is better than any other RTU college as it is a good government college and moreover, it is the topmost college of RTU.
Its average package goes more than 4 lpa, which is better than most colleges.
That doesn't make JECRC a bad college. It is also a good one, much disciplined and organized than MBM.
But, overall MBM Jodhpur is surely a good choice.

Dear Shaily,
You have not mentioned about any particular college for part time MBA. You can follow the below mentioned link:
https://www.shiksha.com/mba/colleges/part-time-mba-colleges-Jaipur
Apart from this you can opt fir MBA through distance education either. IGNOU is one of the good option for distance MBA course. It is a well established brand name and the study material of IGNOU is of international standards. I hope this would suffice. All the best and God bless you.

LNMIIT is far better than both of them because Thapar has very high fees and also, 50% reservation and NIRMA does not have any hostel. So, I speak truly and in a short and sweet way without any long passage.

You can get government colleges through REAP. Just fill up the counseling form and the best private colleges in Jaipur are:
SKIT
JECRC
POORNIMA
ARYA
GIT
BITS, Jaipur