Hi Mohit! Its great you want to take KVPY. Its a quite tough exam and for this you really need to prepare hard, smart and strategically. For this you can join FIITJEE or Narayana they help students to prepare for KVPY and if you can't join these Institutes in such case you need to work hard even more. Do some research on this topic, you will surely find a source to prepare for it and you will also get to know the preparation strategies.

Hello Mohit, You can study on your own by taking up a distance learning program from resonance institute or there are several online KVPY coaching classes being provided for the candidates like myPAT. You can refer to good quality books which are appropriate for numerical like HC Verma for Physics, Arihant for Maths and Chemistry.