What is the correct conduct?

Your answer is correct because in German traffic rules, trams always have priority over motor vehicles, including tractors and cars. This is due to the fact that trams run on fixed tracks and cannot maneuver easily. Therefore, you must let the tram through first before continuing.

The tractor is on a priority road (indicated by the yellow diamond sign), but because the tram has absolute priority, you must allow the tram to pass first. After the tram has passed, you proceed with your intended maneuver.

Remember this rule for future situations: Always yield to trams, regardless of other road signs or the priority of vehicles around you.