Hello,

I hope you are aware of the fact that CAT is one of the most difficult exams in India. So you are going to need minimum 6 months to study everything from the syllabus. CAT includes 3 sections

1. VARC

2. QA

3. LIDR

Now, do one thing, Go through the past question papers and analyse your week and strong section. Most of the students are not good at QA section. Then focus more on your weak section. You must study 8-10 hours a day in order to cover the entire syllabus of CAT in 6 months. Don't only try to solve the questions but, try to solve the questions as fast as possible, speed really matters and you will get only 2 hours for the exam. Try to solve the mock tests and prepare accordingly.  One more thing, Don't skip any section.

I am listing a few books for CAT, have a look

QA Section

1. Arun Sharma's How to Prepare for Quantitative Aptitude for CAT

2. Quantitative Aptitude for the CAT by Nishit K. Sinha

VARC Section

1. Verbal Ability & Reading Comprehension by Arihant Publication

2. R.S. Aggarwal's A Modern Approach to Verbal & Non-Verbal Reasoning

LIDR Section

Arun Sharma's How to Prepare for Data Interpretation & Logical Reasoning for CAT

Nishit K. Sinha's Logical Reasoning and Data Interpretation for the CAT

To know more about CAT 2021, please go through this link

https://www.google.com/amp/s/bschool.careers360.com/articles/cat/amp

Good Luck and prepare hard.