should i read ncert 8 months to complete chemistry for neet in exam?

Yes Chemistry as a subject has a lot of mcqs which are based of NCERT books. Basically NCERT books will help you make core concepts. Make sure you do the questions in NCERT chemsitry book. After you have gone through it then you can refer other books.
But from my personal experience if you do just the NCERT and do justice to it completely, you're good to go. But make sure whatever questions you are unable to solve you get a teacher to explain the concepts.

Also refer to previous year question papers. Solve the relevant mcqs after doing the chapters.

NCERT is the best way to build your concept clear so firstly prefer NCERT books  after completing  that you can prefer the books.

Books for Chemistry

• Physical Chemistry by O.P. Tandon.
• Organic Chemistry by Morrison and Boyd for Organic Chemistry.
• Concise Inorganic Chemistry by J. D. Lee for Inorganic Chemistry.
• Dinesh Chemistry

Books for Biology:

• Objective Biology by Dinesh
• Pradeep Publication's Biology

Books for Physics:

Concepts of Physics by H. C. Verma

• D C Pandey Objective Physics
• Fundamentals of Physics by Halliday, Resnick and Walker
• Problems in General Physics by I. E. Irodov

Good Luck!

Yes, you should read NCERT book to complete your syllabus it will help you to make your base. Alongwith, NCERT to score good marks in NEET you should refer previous year papers and mock test series to check your preparation level.

After, completing youe NCERT you can also go for other recommended books for chemistry like-

• Physical Chemistry by O.P. Tandon
• Physical Chemistry by P. Bahadur
• Organic Chemistry by Morrison and Boyd (For reaction mechanisms)
• Organic Chemistry by O.P. Tandon
• Organic Chemistry Objective by Arihant
• Inorganic Chemistry by O.P. Tandon
• Concise Inorganic Chemistry (For Chemical Bonding, Atomic Structure and Coordination Chemistry)