Firstly you have to studying of NCRT books and make well hand stick notes which 'll helps you in your revision .
There are some important books for AIIMs entrence exam given below:-
Physics-Hc verma physics vol I and II, NCRT of Physics
Chemistry:NCRT of chemistry and textbook of organic chemisrty
Biology- NCRT of biology ,Dinesh objective biology and Trueman's biology
I hope that it 'll helpful for you.