Create a network in Radmin VPN and share network name and password with people you want to play with. This is quite intuitive, but if you facing some issues or want to know more about Radmin VPN network administration here is the guide.
Or you can join Gaming Networks in Radmin VPN: go to Network -> Join and existing network -> Choose tab Gaming Networks
How to set up a multiplayer server in Battle Realms
1. From the main Menu go to Multiplayer -> LAN
2. If you've set up LAN network correctly and somebody hosts a game you should see them in the top part of the screen:
3. Just click on it and you'll be connected to the game.
Troubleshooting
If you can't see your friends or any servers in the game:
make sure you all have the same game version
make sure you did all the steps in the instruction above