From Xojo Documentation

Property (As Boolean )
aWebSession.LanguageRightToLeft = newBooleanValue
BooleanValue = aWebSession.LanguageRightToLeft

New in 2012r2

Supported for all project types and targets.

Indicates that the browser should draw the current language Right-to-Left

In certain cases, languages are typically drawn from right to left. These languages include Arabic, Farsi, Hebrew, Urdu and Yiddish. If the LanguageCode property is set to any of these languages, this property will be automatically set to True.