HEY Swarjapal,

You have scored good percentile in your JEE Main examinations. It's totally up to you whatever you want to give mains again or go for advanced examinations.  JEE Main aspirants securing around 85 percentile will probably qualify for the next stage of the examination i.e. the JEE Advanced examination but this is also not clear.
You should appear for the JEE Main April exam as you will have to just revise what all you have studied and you can prepare for the Advance exam with it also but the decision is yours.

All the very best to you!!