If you have a Creative Cloud subscription you can download a version with right-to-left language support. If you have a perpetual licensed version your bet bet is probably the World Tools plugin from InTools.com.
If you are a Creative Cloud Subscriber you can change the language of the application to be installed change in the preferences of the Creative Cloud Application. After changing it you have to install additional any other language. You can install upon your FR-CH version any MENA version. This will add to the existing version several menus and function which are supporting Arabic or other RTL languages.
InDesign will run in the language of the OS if available, but the functions of other language systems are added and found in mostly localised menu items.