You should be focused to crack your exam. You should refer previous year papers to understand the pattern and level of questions.

Focus on improving your problem-solving speed, which requires continuous practice. Solve as many as MCQs for your practice.

You can refer below recommended books for your preparation

  Mathematics:

    Make sure you can solve problems from the NCERT class XI and class XII textbooks.
    For best concepts, use IIT Mathematics for JEE (Main and Advanced) by M.L. Khanna
    For the most abundant supply of difficult questions: New Pattern IITJEE Mathematics by Dr. S.K. Goyal
    Plane Trigonometry and Elements of Coordinate Geometry by S.L. Loney

Physics:

    Concepts of Physics, Volumes 1 and 2, by H.C. Verma
    Problems in General Physics, by I.E. Irodov
    Fundamentals of Physics, by Halliday, Resnick, and Walker
    Understanding Physics for JEE Main and Advanced (series), by D.C. Pandey

Chemistry:

    Study the NCERT chemistry textbooks for classes XI and XII.
    Organic Chemistry, by Morrison and Boyd
    Numerical Chemistry for JEE Main and Advanced, by P. Bahadur
    Concise Inorganic Chemistry, by J.D. Lee
    Modern Approach to Chemical Calculations, by R.C. Mukherjee
    Physical Chemistry, by P. Bahadur.
    organic, physical, and inorganic chemistry books by O.P. Tandon