which are the best books for quantitative aptitude, DILR, verbal ability please let me know

There are plethora of books available but byfar the best have been mentioned below. 1.How to prepare for Quantitative Aptitude for the CAT by Arun Sharma. 2.Pearson Guide to Quantitative Aptitude for CAT by Nishit Sinha. Moreover, recommended to go through TIME Coaching Institute Material for solved examples and last 5year question sets for Quantitative aptitude. For Easy level problems, or for CMAT and CET preparation you should go with Chandresh Agarwal and notes from CETKing Coaching classes where there is elaborate pattern.

Arun Sharma Material is good for solving practical questions, however to have a strong grip on theory, you should work more towards improving your basics by going through NCERT 10-12.

Also material by TIME is very elaborate.

I am sharing a list of names of books you can refer for CAT preparation.

• How to prepare for Quantitative Aptitude for the CAT by Arun Sharma
• Pearson Guide to Quantitative Aptitude for CAT by Nishit Sinha
• Pearson Guide to Verbal Ability and Logical Reasoning for CAT by Nishit Sinha
• Quantum CAT by Sarvesh Verma

Some other reference books for all sections in CAT you can check in the link below:

CAT Books

It is not important to have quantity of books but quality books. So make sure you have standard books and you are thorough with its preparation.

Good Luck!!