Hi Vivek, 

I am listing down a list of basic books; a thorough reading of the same will serve your purpose. However, please keep in mind that grammar is more practice than theory, so practice as many questions as you can. 

1. English Grammar and Composition, By Wren and Martin [answer key is also available]

2. Word Power Made Easy by Norman Lewis [esentially for Vocabulary]

3. Oxford Current English Grammar

4. Lucent's General English [For Government Exams] 

You can follow Career360's thread and read up more about preparing English Grammar using the link given here: https://www.careers360.com/question-how-can-i-prepare-english-for-competitive-exams

Thanks,