hi plz do understand that IITJEE is a conceptual exam in which u can solve the problems depending on the concept you have learnt from books teachers and other sources your result mainly depends the time you spend in self study the books you have mentioned above are indeed good a few additions would be DC Pandey and R C Mukherjee however since you have FIITJEE and Brilliant's papers they would enough for IITJEE For Bitsat the only area of concern is English which u have to practice regularly if u have the concepts the Bitsat will be easy as u have already prepared for IITJEE cheers!!!!!!!