GORILA.RU Random Item Jump

Can't download the map. That happens often on Magic, especially if you're not from Russia. Magic themselves post maps for download on Discord for that. As for the gorilla, I dunno. If they don't post maps on social media, then either ask admins or friends to send the map.
Also clear the map cache. Located at path Steam\steamapps\common\Rust\maps. Or simply in Steam "Browse local files", there will be a maps folder. Delete all files in it. Try to join after that. If it doesn't work, then delete the map again and ask someone to send you the server map. Then put it in the maps folder and calmly join the server.