Yeah - OK ...
This one's not as straight forward as I thought it was :). I installed and have got something to work with ... but don't ask me to explain it just yet!
In MC6T > Insert Soft Synth DrumBurst
> Choose 'First Synth Audio Output' (from popup Options windows - Instead of Simple)
> Choose Step Sequencer from top right DrumBurst VST window (4th icon in)
> Put one note in the step sequencer to generate a clip in the track
> click on the right edge of the clip and extend it out for say a minute
> from the Tracks dropdown choose Bounce to Track
> it Mixes Down a new track - Audio recorded from about 16 seconds onward
For some reason the first bit is not recorded to the bounced track! (It works from the start in Sonar).
PS: I think the 'difficulty' is because it's a multi-timbral VSTi. Most VSTs are directly, and more simply, recordable by the the method in my first post. TTS-1 is also multi-timbral. There might be other tutorials on that to point you in the right direction.