Nope, TuxGuitar doesn't use RSE (it's a proprietary technology, so I doubt any other program besides GP uses it at all). Written in JAVA, TuxGuitar relies on .gm soundbanks, which... don't sound all that good.
Being a performance-based soundbank at its heart, RSE is hardly the only pebble on the beach, however. You may try looking up a VST-capable tablature editor and running a performance-based VST guitar instrument for sound output.
If you don't mind my asking, though, why is it that you can't use Guitar Pro on a Mac? Not only they do provide a Mac version, you're actually supposed to have got it along with the Windows one, in one bunch. Try asking GP support if you're having trouble finding the download link.