Hello student some of the best books for Hindi grammar are as mentioned below -

General Hindi By Hardev Bahri.

Samanya Hindi By Raghav Prakesh.

RBD Hindi Grammar Language (Hindi Vyakran Bhasya) by Dr. Indira Ashok.

Hindi Vyakaran by Kamta Prasad Guru.

Samanya Hindi- Arihant Publication.

Feel free to comment if you've any doubt

Good luck