Hii

It is interesting to know that You want to Top IIT. First of all stick to the syllabus and level of the exam. Not every book which has written IIT JEE on its cover page is helpful for you. Now you can not skip a single topic of JEE Advance if you want to top in it. So the answer to your question is obvious that you should read each and every topic mentioned in the syllabus of JEE Advance. You need to practice a lot of different types of Questions.