The best books for KVPY Preparation are NCERT Books. However, there are a few reference books that you can prefer for KVPY.

Click Below link

KVPY Preparation Books

Hi, In general you should focus on your NCERT books to get the best results!

Apart from this you can refer to the below material:

Physics:

• Fundamentals of Physics : A Must-Have Resource Book
• Concept of Physics by DC Pandey

Chemistry:

• Moderns ABC of Chemistry for Class – XI With CD
• NCERT Physical & Organic Chemistry

Maths:

• Mathematics For Class XI

Biology:

• Elementary Biology (Volume - 1) by K.N. Bhatia, M.P. Tyagi; Publisher: Trueman

Hope this helps.

All the best for KVPY.