Is ncert at your fingertips biology is necessary for preparing for aiims
but remember NCERT is not sufficient..
Because the paper is made by cbse and their syllabus is NCERT .
But some questions Come other than the NCERT .
So to conclude do NCERT at its core but read little bit extra while doing questions and revision.
prefer a few other books to help u with questions.
Hope it helps you.
Regards
Dr Parmanand Agarwal
MBBS MD
Career counsellor.