Group Video Call

mayankdixit  the Group Video calling supported with up to 350 participants now https://docs.microsoft.com/en-us/azure/communication-services/concepts/voice-video-calling/calling-sdk-features#detailed-capabilities 

Here is documentation how you can place an ad-hoc 1:N call to another ACS user or a phone numner https://docs.microsoft.com/en-us/azure/communication-services/how-tos/calling-sdk/manage-calls?pivots=platform-web#place-a-1n-call-to-a-user-or-pstn 

You can also use Group ID for meetings alike scenarios https://docs.microsoft.com/en-us/azure/communication-services/how-tos/calling-sdk/manage-calls?pivots=platform-web#join-a-group-call 

Please let me know if this helps.