as you can understand from the project name I need a web site.
In this web site, some users can get together and make a web conference (video and audio) in a certain session.
For example, there can be 4 users that are making video conference in conference room 1 and there can be 5 users in conference room 2.
Your UI is not important and you do not have to make very good looking web site. Important thing is your software.
Programming language will be Asp.Net and you can use any libraries like WebRTC, SignalR or etc...