Hello Aspirant

Some of the best english grammar books for competitive exams are:

1. Objective General English by SP BAKSHI
2. Wren and martin english grammar book
3. Plinth to paramount English by Neetu singh
4. Word power made easy by Norman Lewis (Mainly for development of vocab)
5. Above all refer to previous year solved papers of english by any good publications

Hope it helps

Thank You & Good Luck!!!