If your battlenet your best shot is to look into makehost.com or going through blinkgaming. Custom Hero Arena tends to be more popular over the Euro Realms. Like when its hosted and fills the split is like 1-2 from the US/CA/MX and the rest are mixed of different European countries. So maybe look into the Europe channels of garena or something. They're based on levels I heard sorry I dont know how garena works so that might effect the player base if your a high level chat room they may only want to play dota.
