Hello Lakshya,

There is a very sort range of books are available in hindi medium for IIT JEE preparation but still you will able to get the best one for yourself, here I'm naming those:

1- Physics concept by H.C. Verma (Vol I & II)

Problem in general Physics by I.E. Irodov

2- Organic Chemistry by O.P. tandon

Inorganic Chemistry by J D Lee

3- Math's by R.D. Sharma (both 11& 12)

Target IIT Mathematics by AP Verma

* Don't forget to learn from NCERT as these are the best books for all those 3 subjects which will clear your each and every basic point and these are also available in Hindi version.

Try to grab the coaching notes of biggest coaching center, you can take it by any of your friend and it will be easily available in Hindi as well.

Good Luck!!!