Dear candidate,

You can firstly refer to books by Arun Sharma for Verbal Ability.

Word Power made easy is another great book.

It is also recommended to have great comman over English which would only come by reading self help books, Financial newspaper and News channels like Bloomberg, ET Now, CNBC Bazar.

For indepth preparation check below:-

Always follow modern day Bottom Up approach to understand views of the author, and tone of passage where questions are read first and then the passage. Then you should summarize the passage thoroughly and eliminate all wrong options. For almost similar options select yhe one which fulfills the question requirement more and for that you need more and more mock tests and analysis of the approach you have. For complex passages, it is recommended to go for book named 'word oower made Easy' to understand all jargons and Different synonymous words.

Hope I answer your question and it's helpful.

All the best!