If you have a well preparation of NEET or JEE Mains level then you will definitely do well. The key facts for physics is to have a imaginative mind , logical thinking and application of concepts. JEE and NEET both offers more or less logically intricate problems so with that you can solve problems in kvpy quite a lot.

I would also recommend you to have good info about theories so that you can attempt more conceptual problems if any come into the exam. Also practice a lot so that you can coup up the speed as a result your accuracy and speed both will increase.

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