For scoring very high percentage in board examination, I suggest to go through NCERT books only.If you are planning to crack I.I.T. entrance examination or medical entrance examination then study additional books. For mathematics, I recommend books by RD Sharma and RS Agarwal. RD Sharma is recommended for topper students. RD Sharma has added few questions of very high level. Whereas mathematics books by RS Agarwal is of medium level. Lots of model papers and revision tests are there at the end of each chapter.
For science subject i.e. Physics, Chemistry and Biology, books written by S Chand are best suggested.Books written by RD Sharma, RS Agarwal and S Chand are recommended in addition to NCERT book. NCERT books are core books. You have to be thorough with NCERT books to score high percentage in board examination. For your kind information grading system has been abolished from 10th class. Again board examination system has been introduced from 2017 onward.