dear riya, 

First of all best of luck on your preparations to crack AIIMS exam in the upcoming year. I would like to list out the useful books that may help you in your preparations:

• NCERT Chemistry and Biology thoroughly (I mean it literally thoroughly!)
• NCERT points to remember only from NCERT Physics (can skip unwanted parts). Trust me this will be surely be helpful for your A&R in AIIMS Physics
• Physical Chemistry Book O.P.Tandon (For your weak topics only. Only and only for your weak topics PLEASE!)
• H C Verma Physics (Only for your weakest topic in physics to build concept of that particular topic ONLY!!!)
• NCERT Gear UP Physics by Himanshu Udaiyinia (Do all level questions from level 1 to HOTS)
• NCERT Gear UP Chemistry by Dr Manu Kaushal (Do all level questions from level 1 to HOTS and do the assertion and reason section to see expected AIIMS questions)
• NCERT Gear UP Biology by Dr Ajay MohanMohan (Do all level questions from level 1 to HOTS including the expected image based question section too)
• NEET 31 years solutions (Phy,Che,Bio) by AIM4AIIMS/NEET
• AIIMS 24 years solutions with GK and GK, aptitude and image based questions by CBS Publishers
• Assertion & Reason Book (Phy,Che,Bio) by Aim4AIIMS
• Have only One concise guide book which is NCERT based per subject
• All other books you should either avoid or try to use it just as a reference book to solve your doubts or to build some of your really weak parts in a subject
• . Believe that “Revision is the key for success and thats not possible if you are following big big books and there is no point doing research on a chapter or subject, You have to cover 3 subject pretty well and practise as much questions possible”.
• Have a habit of having 3 small books each for a subject to note very important facts and data which you are liable to forget easily and also a separate section in that book for all the mistakes you are committing in your exams. Revise them again and again and this will be handy for your last 2 months preparation for your exam.

hope it helped.