In order to play a race that is not available in vanilla NWN, you will need the PRC Character Creator -
http://nwvault.ign.c...d=77601&id=1417
Use it to create your new Drow character. The generated .bic you save to your local vault folder.
When you start the Mod (with the PRC injected), you pick this .bic (saved character).
A big thanks to Ben Harrison for doing the work on this version!