Physics:H.C. Verma: This book is the Bible for IIT JEE physics. You have to be thorough with each and every word of the theory in this book. Also, solve all the objective and short answer questions with diligence. They can be shamefully easy. However, unless you solve them, your concepts will not be crystal clear.
Cengage (by B.M Sharma): This book is excellent for both theory and problems. It will teach you many new concepts, which you will be able to appreciate after being thorough with Verma. Also, solve the problems of this book with diligence.
Chemistry:The official NCERT books are extremely important.Complete them from cover to cover.
For physical chemistry, refer to NCERT and Cengage for theory. Solve problems from Cengage.
For Inorganic chemistry, be extremely thorough with NCERT. After that, take a look at Cengage.
For organic chemistry, no book beats Morrison and Boyd. Read all the topics of the IIT JEE syllabus from here;(after NCERT).
Mathematics:The only key to master Mathematics is to practise a lot. Also, you need the ability to independently solve tricky problems.
Whatever you select complete it thoroughly.