For entrance exam like jee main you will surely need ncert and with ncert you can surely grab good marks but ncert is best known for its concepts and questions which gives the best idea and information on any topic but one needs to be more better than that if he or she Is serious about IIT.physics1.ncert(best for concrete concepts)2.hc Verna vol.1 and 2( considered as bible of physics.after these two books almost everything gets covered and one can easily crack jee mains with super good marks but for jee advance I would prefer one to add one more book and that is complete set of physics by dc pandey. now you can be sure about physics. usually people say if you are 100% in these books then for brushing your skills in physics one can solve problems by IE IRODOV(this is very high level book and preferred that it should be done at last that is at time when you believe that you have done 100 in above books.maths1.rd sharma 11th and 12th and ncert for sure 2. at this point you have a good choice either you can buy objective problems by rd sharma or some other set of books like by arihant publication or cengage.most prefer to do rd sharma but hey others are a good choice and their is nothing risk taking if you chose others on rd sharma. one of the best choice are IIT Mathematics books by DasGupta and also by M.L. Khanna. these two books that is ml khanna and das Gupta are very good books . I bought ml khanna. 3. here I want to tell you about some classic books and they are, higher algebra by hall and knight, coordinate geometry by sl loney, plane trigonometry part 1 by sl loney,Differential and Integral Calculus by N. Piskunov. these classics are considered a must like coordinate geometry by sl loney do have some problems which are of JEE level.remember one thing in maths one needs to solve a lot of problems and don't buy so many books you are not supposed to buy all of above given books but rd sharma and ncert off 11th and 12 are necessary as they makes basic concepts and if you still have to choose than you can choose rd over ncert of 11th and 12th.about higher level books you are at least supposed to solve at least one complete set of book like vol 1 and 2 of objective problems by rd sharma or 5 set of books by ml khanna.chemistry1. 11th and 12th class ncert is considered must.2. inorganic in inorganic ncert of 11th and 12th ncert is enough and nothing else.3. physical( you have two choice)most preferredModern Approach to Chemical Calculations by RC Mukherjee is enough for physical chemistrynot necessary but this 2nd book you can think ofUniversity Chemistry by Freedman and Young for Physical Chemistry4. organic here you have 3 options Organic Chemistry by Morrison and Boyd or Organic Chemistry by lg wade ororganic by Solomon's and frhyl organic requires least mugging and most understanding and building concepts. these books are different from other books remember that . I bought lg wade.ncert is must.I prefer you to go through this linkhttps://googleweblight.com/i?u=https://jeemainonline.in/best-books-jee-main-advanced/&hl=en-IN&geid=1029

Study NCERT books and be confident. you should also solve previous years question papers which will tell you how much is your preparation before attempting the specific examination.