If you want to take admission in engineering program you should apply for as many as options.

You should apply for other exams of engineering as well like your state level entrance exam, BITSAT, VITEEE, SRM, Amrita and Manipal.

If you don't score well in your JEE Main to get NITs/IIITs and GFTIs there are many private colleges as well who take admission on the basis of JEE Main you can appy in these colleges. You have to apply seperately for the application form of these colleges

You can check the list of the colleges below

List of Private colleges through JEE Main

There are few colleges as well who give admission directly on the basis of class 12th like amity and sastra.

You should try to get admission in top colleges of engineering which offers good placements.

Good Luck!!