Secure Group Calls. Telegram's secure calls can be easily expanded to hold up to 200 users – all protected by end-to-end encryption.

Telegram calls can be used for anything from spontaneous chats to job interviews:
• Add other users to an active call by tapping in the top corner.
• Start a call with several users via the 'Calls' tab or Settings > Recent Calls – tap 'New Call' and select multiple people.
• Send a link to the call to create scheduled meetings or invite multiple groups.