rfa to sat conversion essentially represents export of data from Revit files (.rfa) to 3D ACIS format (.sat), something that is doable with Revit itself and perhaps some other alternative products that support Revit files.
If you do not have access to Revit, you will have to ask someone who does to do this export for you as there are no free converters available for this task.
Updated: September 7, 2023