It always means the last known position of the Fellowship (where the token is on the board). This is Rivendell, or the last place the Fellowship was declared or revealed. When the Fellowship is on the Mordor track, it is not in any region.
Is that the region before the fellowship moves or after?
Remember that the Fellowship figure does not move on the board when you move the Fellowship as an action. That only happens when the Fellowship is declared during the Fellowship phase or revealed by a hunt tile with the reveal icon.