Colleges in Gujarat

Sardar Vallabhbhai National Institute of Technology Surat
Nirma University, Ahmedabad
Dhirubhai Ambani Institute of Information and Communication Technology
Maharaja Sayajirao University of Baroda, Vadodara
Pandit Deendayal Petroleum University, Gandhinagar
Institute of Infrastructure Technology Research and Management
Institute of Engineering and Technology, Ahmedabad
AD Patel Institute of Technology, Anand
Institute of Technology and Management Universe, Vadodara
are some of the institutes accepting JEE Main scores.

Highest package is about 10-15 LPA.
Average package is about 4-6 LPA.

You can get admission in Nirma via 3 ways:
Through your class 12th boards and ACPC rankings.
Through JEE Mains marks.
NRI quota.

You can refer to the link to have detailed information: https://www.google.com/amp/s/www.shiksha.com/science/course/amp/m-sc-in-environmental-sciences-gujarat-university-navrangpura-ahmedabad-270210.

There are three ways through which you can get admission in DA. One through the AIR of JEE Mains or if you are a Gujarat domicile, you can get in through ACPC through GUJCET. In case you are an NRI, or anyone of your parents are NRI you can apply for admission through your SAT score. There are no other entrances conducted by the college for the UG programme.
Hope this helps.

It all depends on your AIR. Given that, you got 71% in JEE Mains, I am assuming you have a score of 255-256 which brings you a rank of around a maximum of 3K which means you have a guarantee to get in DA-IICT. The cut-off ranks are around 12K.
Hope this helps.