Not a Tram.
Here's an SWR sweep of a Diamond D130N discone I did a few years ago. Sweep is from 30MHz to 1.2MHz, the advertised capability of the antenna.
——NOTE----
SWR is NOT the only measure of antenna performance. NONE of this takes into account the radiation pattern of the antenna. This ONLY tells you how well the antenna is doing something with the RF other than sending it back down the pipe.
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Answer, SWR on 6 meter band isn't great. It's a loaded antenna. There's not a good ground plane under it. It'll "work" in the sense that it will hear a strong signal, and it'll radiate some amount of your transmitted signal.
I've never used on on 6 meters.
I cannot imagine that it would work well. I'd imagine that ANY purpose built 6 meter antenna is going to work better.