First you have ask yourself that are you able to solve all problems of NCERT including excmpler problems without any help.
If yes you are already prepared for JEE MAINS.
If no then you will have to diagnose what is the cause of issue as there can be many
Have you mastered trignometry as many integrations problems are based upon manipulating trignometric formulas.
Similarly you should be through with Log and Polynomial Functions.
IF you follow NCERT step by step and solve all problems with little help you can master the techniques.
Instead of going for any advanced book, go back to basics and pick up NCERT.\
I am MSc in mathematics but still refer to NCERT for fundamentals. Hope that helps
