Your Application may look something like this

SUBJECT : Permission to Join Offline Classes

Respected Sir/Maam

Hope you are Safe and Hearty in these Tough Pandemic Times. I am _______ , a student of Class ____ Section ___ of your esteemed school. I would request you to grant me permission to continue with Offline Classes for the remaining session.

My locality faces regular and severe network issues, which makes it difficult for me to continue with Online Classes, and hence the need for Offline Classes. I would be obliged if you grant me permission for the same. Hoping for a Positive Reply.

Regards

Your Name