plz tell me about which are the best books for class 12th (PCMB) and IIT JEE and NEET exam without ncert I'm not purchase any coaching or tution and I'm doing self study but I'm not studying in class11th better so tell me what should I do...??

Hey there hope you're doing well.
Dear aspirant, although the depth of study required in IIT- JEE and NEET/AIIMS are different some books are common in their preparation. For NEET preparation was also suggested by toppers who took this test NCERT are the must you should read as more than 50 to 60% questions in NEET are asked from concepts given in NCERT books. Still for physics section some suggested books are:
1.NCERT class XI & CUI
2.COP by H.C.VERMA. 1&2
3.Objective Physics by D.C.Pandey
4.Fundamentals of physics by Pradeep.
You may also go for physics by Resnick Halliday Walker.
For chem. Section the recommended books are:
1.NCERT class XI &XII
2.Concise inorg. Chem by JDLee
3.Chem. guide by Dinesh
4.Practise objectives from phy- N Awasthi,org- M.S.Chauhan, inorg.- V.K.Jaiswal.
5. OP TONDON chem books
The books are also recommended for IIT-JEE prep.
For biology:
1.NCERT class XI & XII
2. Bio. By Pradeep & Dinesh
3.GR Bathla books for bio.
4. Bio Vol.1&2 by Trueman
I think these would be enough for your prep.
Rest is your dedication and hard work along with consistency.
Thank you hope it helps you!