Hey there

KVPY is an exam whose syllabus is similar with syllabus of JEE so i suggest you stay preparing for JEE and along with it you have to do some extra things to clear KVPY. For KVPY first go through previous year and analyze the whole pattern of question and then start preparing accordingly like chemistry has various theoretical questions so do not ignore inorganic, physics rotation, thermodynamics, waves are very important, maths is a subject of practice do practice a lot.

For JEE preparation

https://learn.careers360.com/

good luck