There are 3 versions of the language file, you only need to install one.
Chose one, and extract it to your server's /data/lang folder in your amxx folder.

Only use the version with special characters if you are sure your mod supports it (e.g. NS does, CS does not).
For the UTF-8 version I am not sure about anything at all, you will just have to try.

If unsure, choose the default version.
