Can you please tell me if it is possible to deploy your own jitsi server inside the local network (without access to the Internet).
If possible, how to do it?
Absolutely possible and done by many. The server itself will need internet access to install (and on-going security updates etc).
If you follow the install guidelines Self-Hosting Guide - Overview · Jitsi Meet Handbook the only things you will need are
- local DNS entry for the server name
- A validated internal SSL certificate for the DNS name (how you sign it I presume you have internal procedures for that, else use letsencrypt with a “proper DNS name” which internally resolves to your local IP address
Other than that should be fine.