JEE Advanced

I think according to your category you should be able to attempt Mains.

With 80 marks in JEE Mains, I don't think you will get selected for the JEE Advance. You need at least 95 - 100 marks to sit for JEE advance ( obc ).

First, you should get your basics clear. For that read the theory, clear your concepts. You can refer to HC Verma for basics. Then you should practice different questions. I found book By BM Sharma from Engage Publication very useful. Also keep giving mock tests continuously. Try solving a variety of questions.

It would be better ti prefer VIT or SRM. I would suggest you to not take a drop.

You must have science in your class 12th from any recognized board and must have secured 75% in the board exams.

Just go through this link and fill out the required details:
https://www.shiksha.com/college-predictor

If you are capable to pay high fees then you can choose BITS otherwise IIT is the better option.

Just go through this link and fill out the required details:
https://www.shiksha.com/college-predictor

Just go through this link and fill out the required details:
https://www.shiksha.com/college-predictor

Following topics:
Heat and Thermodynamics
Current Electricity Kinematics
Electrostatics
Modern Physics
Capacitance
Wave Motion Physics of Nucleus Circular motion
Rotational Motion
Electromagnetic Induction 2D
Simple Harmonic Motion
Radioactivity Vectors
Laws of Motion Kinetic gases
EMW (Electro Magnetic Waves)
Wave Optics Center of Mass, Momentum and impulse
Work Power and Energy Solids and Semiconductor Devices
Units Dimensions and Errors Elasticity
Gravitation
Fluids.