Through JEE Main you can take admission in both government and private colleges.

For government colleges you can apply for NITs/IIITs and CFTIs. Make sure you have 75% marks in your boards exam or you should be in top 20 percentile for general category and for SC/ST it is 65% marks to take admission in NITs/IIITs and CFTs. You have to attend JoSSA counselling for it.

You can also apply in DTU and NSIT. Counselling will be held through JAC Delhi.

There are many top private colleges as well who consder JEE Main marks to provide admission. You have to apply seperately for these colleges.

You can check the list below

PSG College of Technology, Coimbatore

SASTRA University, Thanjavur

SSN College of Engineering, Kalavakkam

Thapar University, Patiala

Amity School of Engineering, Noida

To check the complete list you can refer beow link

Top Private Engineering Colleges through JEE Main

Good Luck!!

JEE Mains are the entrance exam for NITs, IITs and GFTIs. So these are the best colleges to apply after the IITs. As for other institutes and states that take through JEE Main, I can only suggest if I know your home state where you are doing your class 12 from. Some private universities that take JEE main are DAIICT, Nirma, Sastra, Jaypee, Thapar, IIIT Hyderabad