First you should make a proper and programmatic study schedule which you'll follow throughout your preparation. Before starting your preparation, you must check the entire syllabus. Instead of choosing a random topic from the syllabus, you must break your preparation into sections. Sub-topics from each section should be selected and then strategy on clearing concepts must be made. If possible make short notes. These will help you in revision. Never leave any concepts doubtful or unsolved.

Once done with the syllabus and concept clarification, you should move towards solving previous years papers. Give mock tests as much as possible. Time management is one more important thing you should look upon. Remember that practise will increase your efficiency.

Undoubtedly, NCERT Textbooks of class XI and XII are best books for preparation. You can get the best books like HC Verma for Physics, OP Tandon for Chemistry, RD Sharma for objective Mathematics.

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