B.Tech

Yes, Chandigarh University is a good option.
For more details, kindly visit:
www.cuchd.in

Yes, you can register in open category. See, at the time of counselling talk to the administration department. They will provide you proper guide lines for this.

Please check about the course on www.cuchd.in

You have many colleges like G L Bajaj Institute Of Technology And Management, Galgotia Institute Of Technology, JSS Institute of Technology, Ajay Kumar Garg Engineering College I.T.S Engineering College and many others.

IIT Khagarpur
NIFTEM, Sonipat
Central Agriculture University
Chemical Department; Panjan University
NIT, Rourkela

See, you will have mechanics of solid, fluid mechanics, industrial sociology and many others. You have to refer foreign authors in respective fields.

No, sorry to say, but you cannot get admission with this percentage. Your rank is also not good. It is in lakhs. I will suggest you to fill improvement form and try for good colleges next year.

JNU does not offer B.Tech or B.Sc degrees. You may refer to JNU e-prospectus:
https://admissions.jnu.ac.in/Default2.aspx#

The choice is yours as what you want to pursue to get better career options.
Kindly visit:
www.cuchd.in