For each of the supported languages, the Revit software contains translations for the user interface.
Revit does not use language packs. Instead, the base language for the software is determined as follows:
To use Revit in another language, users can modify the desktop shortcut. The installed software contains translations for the user interface for all supported languages. You may need to install additional content packs to support the languages and locales in which you want to work.
For each user, the Revit software uses a single Revit.ini file, stored in the user profile folder (C:\Users\<username>\AppData\Roaming\Autodesk\Revit\<product name and release>). All languages use the settings defined in that Revit.ini file.
When you install the software, you also typically install Autodesk Revit Content Libraries. Select, download, and install the content packs for the languages you wish to use from the Content Download Page .
For online help (when connected to the Internet), by default, users go to the Revit help site for the language selected for the Revit software. If you always want to access online help for a particular language, regardless of the language being used for Revit, edit the Revit.ini file to define the OnlineHelpLocale setting in the Documentation section.