Now i am in class 11 and want to prepare for jee mains these two years ...give me some tricks to prepare for both jee mains and boards

Hello Shamith
Hope you are doing well!! See basically if you study from NCERT books then 50% preparation of JEE mains will be done and for chemistry it will be 70% now from NCERT books if you study and if your concept is clear in each subjects then you can crack the JEE mains exam. But by cracking JEE mains your job is not done if you want to get into top NIT's then your rank should be very good and for that you just need to study hard, you have to solve problems from different competitive books. And do solve previous year question papers of JEE mains you can do it from Arihant 39 years solving problems. And so called preparation for board exam rather then physics, chemistry and mathematics if you prepare for JEE mains it will automatically cover the board's syllabus. Some theory and all you have to see. And rather then literature subjects you just need to give little time. But i would like to say don't take board exam lightly as you need to score above 75%. So you have enough time and you should have proper grip in 3 subjects and maje all your doubts clear and act accordingly. You can chase your dreams. Hope these will help you regarding any query feel free to ask in comment section.
Good luck for your future.