https://support.unity3d.com/hc/en-us/articles/2096...
Resolution
Unity offers a free amount of Concurrent users (CCU) for each license.
- Personal: 20 Concurrent Users
- Plus: 50 Concurrent Users
- Professional: 200 Concurrent Users
If you need to increase the number of CCUs that your game supports then you can set this when you submit a live request via the multiplayer dashboard. If you do this, you will be charged $0.49/ GB of traffic that travels through the Unity infrastructure (Matchmaker, Relay Server). This means that you pay for the extra bandwidth that you use.
We also have a way to estimate your monthly bill. This can be found by scrolling to the bottom of the multiplayer page.