Hello student some of the best books to prepare for NDA examination are as mentioned below -

1. Pathfinder for NDA & NA National Defence Academy Naval Academy Entrance Examination-Arihant Publication
2. Study Package for NDA/NA Entrance Exam- Tata McGraw
3. Chapter wise-Section wise Solved Papers NDA & NA - Arihant

For more details refer to the link mentioned below - https://www.google.com/amp/s/competition.careers360.com/articles/best-books-prepare-for-nda/amp

Feel free to comment if you've any doubt

Good luck