the TRG makes a great platform for all kinds of good calibers like the 243, 260, 6.5 Cm and the 6 CM goes without saying.
go for it, it will be a really cool stick.
I'm not too familiar with the 6CM but the TRG has a long mag for the caliber so I would suggest using as long of a 6mm cartridge as possible to make use of the room. Magnums won't work of course but I've loaded a .308 out past 2.91".
Justin