Hi aspirant,

Following are the list of best books for preparation of JEE Mains in Hindi medium:

• Physics:
  1. Concepts of Physics (volume 1 and 2) by H.C. Verma
  2. Problems in General Physics by I.E. Irodov
  3. Fundamentals of Physics by Halliday, Resnick & Walker
• Chemistry:
  1. Numerical Chemistry by P. Bahadur
  2. Organic Chemistry by  Morrison & Boyd
  3. Inorganic Chemistry by J.D. Lee
• Mathematics:
  1. Maths XI & XII by NCERT
  2. Trigonometry by S. L. Loney
  3. Co-ordinate Geometry by S. L. Loney
  4. Higher Algebra by Hall & Knight
  5. Problems in Calculus of One Variable by I.A. Maron

Keeping in mind that you have asked for One book per Subject, do go for the first book in priority wise (as mentioned).

Also, for Chemistry since there are 3 parts (physical, organic and inorganic), all the 3 books are necessary.

All that said, it will be my advice that try to go through all the books mentioned as all these books are really good and will help you crack Mains and as said Practice makes you Perfect.

Hope this helps. All the best.