IIT

Hello Sunny,
JEE Mains and JEE Advanced cover the same subjects but they have a different difficulty level of questions. JEE Mains questions are straightly asked while the questions asked in JEE Advanced are very tricky.
For JEE Mains you must cover all the NCERT books for a stronger base. As concepts are very important for cracking JEE Advanced, you will have to build concepts strongly. For this you can refer the following books:
Following are the books:
1. Physical Chemistry by RC Mukherjee.
2. For Inorganic, you can go for Concise Inorganic Chemistry by J. D. Lee.
3 For Organic, you can go for one of the following books:
A. OP Tandon
B. Morrison and Boyd
C. Himanshu Pandey
For Mathematics:
RD Sharma for Objective questions (mandatory)
Higher Algebra by Hall and Knight
Calculus and Analytic Geometry by Thomas and Finney.
Coordinate Geometry by SL Loney
Trigonometry by SL Loney
For Physics
1. HC Verma (mandatory)
2. Optics, Modern Physics, Waves, and thermodynamics by D.C Pandey.
3. Cengage Publications Mechanics Volume - I & II
4. Cengage Publications Electromagnetism
Hope this will help you.
Best of luck.

First, decide yourself what you want to do MBA or job, because if you are planning for a good college then I would rather suggest you to study for CAT exam with complete dedication of taking admission this year. CAT needs a lot of practice and study to get admission in good colleges. If you waste time in deciding these confusions you will not able to give CAT exam at good stage. So I would suggest start preparing for CAT entrance exam with complete dedication and Self-motivation. Then if you get a very good score go for TOP MBA colleges to complete your goal and if unfortunately you couldn't able to crack CAT exam then you can go for any suitable job for one year then you will have time and you can prepare will for next CAT exam.
While doing your final year you will have a flow of study for CAT and at least you will not waste a year for preparation of CAT.