Which books did u followed during your CAT preparation? Pls suggest some good online & offline sources for preparation ?

You would require to give atleast 20 mock exams befor final CAT exam. Moreover , keep revision of your frequently committed mistakes and negative scored questions to eliminate them. You can use books by Arun Sharma for quantitative aptitude and lOgical Reasoning, Nishit sinha for Data Interpretation, CaTking notes for Verbal ability. You can also refer books by Arihant Publication for Quants. For Onljne mock exams go with Oliveboard, Testfunda, HitbullsEye. Make sure you practice more and more ro make your mistakes redundant, focus on questions where you're going negative.

I found the Sarvesh Sharma book for quant really useful provided you can actually complete it. It has detailed and extensive quay exercises with varying levels of difficulty and solutions are also lrovided ao you can know whimat is the fastest way to solve a question after you are done with your exercises. It will be really helpful if you are able to complete the book.

Online you cab look at testfunda or oliveboard as they not only offer a large variety of customized tests, but they also offer mock tests which a lot of people give. It helps you gauge where you stand.

Also follow the news often. Install apps like economic times or business standard which will help you stay in touch with what is happening in the world and around you.

I found books by Arun Sharma to be very helpful especially for QA. For VARC it would benefit you if you read a lot everyday be it novels or newspapers or any topics that you like to develop your RC abilities and learning certain rules/techniques such as skimming (You do not have to be a master of grammer but  knowing certain rules do help). For DI/LR there are certain limited type's of variety of questions(in a broader sense for example, questions related to table/circle in LR) and figuring such questions and practicing them would help you to develop your skills and reduce the time taken to solve such problems. I hope this answer helps you.

Some classic books thatvare generally recommended are:
Charles Dickens: Hard Times
The Tale of Two cities
The one minute manager
The last muhgal
1984
Freakonomics
Kite runner
You can find some of them in PDF form from the internet. For others, you need to buy hard copies.

However, I strongly suggest not to focus too much in reading books and rather read as many Newspaper and magazines editorials as possible. They give the best flavor for all round topics!