The Tales of Raviganion is a Total Conversion that replaces all the original Warcraft 3 races with new ones: Humans are replaced with Wood Elfs, Orcs with Trolls, Undead with Chaos and Night Elfs with Swamp Dwellers.
The mod is a melee mod, which means it doesn't have a campaign or anything like that. The mod plays on any normal wc3 melee map and uses it's inbuilt unitdata to override the settings in the map. So in short, there are three ways to play TToR; Local Area Network, Custom Game and Battle.net custom game. Have in mind that maps with custom trigger and unitdata will not work with TToR.
Example maps are Tower Defenses or Hero RPG's. Only melee maps works with TToR, that means all the maps that comes with wc3 and tft (except the custom scenarios).