Another 12 "Language Interface Packs" are now available for Office 2013: 

This follows the first 3 Language Interface Packs (LIP) announced a couple of weeks ago: Basque, Catalan and Galician.

If you want to know when your language becomes available, bookmark the Office Language Interface Blog where these announcements are made. You can check this spreadsheet to see if your language will be localized for Office and Windows.

To learn more about what's new for language support in Office 2013, have a look at this post by Julian Parish on the Office Next blog.