That would only work if they do have multiple versions. Some games, like Pokemon Sun/Moon, are the same for all regions.One EUR copy and one USA copy perhaps? Dunno, never tried it myself.
so say if i wanted two of the same game installed at once how do it
^ This. See this thread for details on how to change the titleID:Changing the title ID might be possible, but I'm not completely certain how to do that.