B.Tech

Following are the best options for you:
Osmania University
St. Joseph's degree college

IIT-Bombay and Kanpur are the best options for nuclear engineering .

Yes, you can take admission in IMU if you have passed your 10+2 with more than 60%.

Following are the good options for you:
Aravali College of Engineering and Management
Manav Rachna University
Ganga Institute of Technology and Management

Following are the good options for you to pursue B.Tech:
Assam Kaziranga University
Assam Science And Technology University

Yes, embedded is a very good choice as it has more scope in the future.

Unfortunately, I don't have this information because the university doesn't disclose this information, but it varies every year. So, I would suggest you to give your best in the JEE Mains and then contact the college authority to know if the marks achieved by you are good enough to get admission or

Yes, you can get admission in a government college as you have secured a good rank.

Following are the best options for you:
Girijananda Choudhary Institute
Assam Engineering College
Jorhat Engineering College
IIT-Guwahati

LNMIIT will be better than Shiv Nadar University. Earlier, placement was the problem there but things have been changed now. Placement is just too good there.The faculty members are very experienced and work hard for the future of the students. Also, the campus is very beautiful.