If you want to become a fighter pilot in Indian Air force then jee main won't help you.

to become a fighter pilot in Indian Air force you have many options at the just after 12th you appear for NDA and then select Indian Air force as your first priority. The other option is you appear for CDS after your graduation and choose Indian Air force is your first priority.

in no way appearing for JEE main would help you to become a fighter pilot in Indian Air force.

To become a fighter pilot in Indian Air force you need to meet very extreme physical standards and endurance test. The eyesight must be very strong and the response must be very good and fast.you need to appear for SSB interview in any case and only if you able to qualify the SSB interview then you will become a pilot in Indian Air force after extensive training.