If you are describing what I think you are, no. The issue would be that both rim edges are not parallel to each other so squeezing them both in a vice at the same time would be a bit rough and cause flexing. Do one side at a time.
If you look the rim, the edges flare outwards from each other. The steps are to take two thin and narrow strips of wood and place them in the vice. Next, insert one rim edge at a time in between and compress the vice, causing the bend to straighten until parallel. They have to be fairly narrow (top to bottom) as you can see that when the rim drops into the vice there is only a little bit that it slides down before it will strike the inside of the rim. Hence the suggestion to use a rag, it's usually a bit easier to work with and all you are really doing it providing a buffer between hard steel of the vice and the softer metal of the rim. Have fun