For IIT JEE, You must complete your CBSE Books as they are mandatory for building a strong base for concepts. But to crack IIT JEE, you have to go for other reference books also to practice more and more quality questions. So here I am providing you name of some of the best books to prepare for IIT JEE 2018 : For Chemistry 1.Physical Chemistry by RC Mukherjee. 2. For Inorganic you can go for Concise Inorganic Chemistry by J. D. Lee. 3 For Organic you can go for one of the following books: a. OP Tandon b.Morrison and Boyd c.Himanshu Pandey For Mathematics RD Sharma for Objective questions (Mandatory) Higher Algebra by Hall and Knight Calculus and Analytic Geometry by Thomas and Finney. Coordinate Geometry by SL Loney Trigonometry by SL Loney For Physics 1.HC Verma(Mandatory) 2.Optics, Modern Physics, Waves and thermodynamics by D.C Pandey. 3.Cengage Publications Mechanics Volume - I & II 4.Cengage Publications Electromagnetism Hope this will help..!! Best of Luck..!!