You visit the link for expected cut off of KVPY 2021:

https://school.careers360.com/articles/kvpy-cutoff

The questions asked are basically based on to know your personality and that how much confidently you are answering them , also on your subject knowledge like :

1. Tell us about your family and friends
2. What are your hobbies
3. In mathematics most probably mostly questions are on identities and geometry.
4. In Physics , questions asked on the topics semiconductors . current , voltages etc.
5. And In chemistry . Questions are on enzymes , DNA and Blood groups.

I hope my answer helps. All the very best for your future endeavors!