I've installed the Elin Race with all compatible versions of the requirements for the skyrim version i'm running.
The mod is present within the game but it strangely won't show up in the Race Menu.
I am using Skyrim v1.6.353
The Tera Elin Race i'm using is the Remastered version from Acro748 and it's the most recent update (v1.2.3)
EDIT: Updating RaceCompatibility to the most recent version fixed this.