I don't have a 6900. I have a 1600 that's running v9.4.7 and when I pass traffic through this box, I see tmm utilization graphs for all tmm's.
Are you passing traffic through the box? "b virtual show all" should show you this data at the CLI or you can use the GUI too to verify that your virtual is passing traffic.
tmm0 typically handles "other" system daemons + traffic too so the "tmm0" line could be due to other system daemons?
If you are passing traffic through your virtuals, could you post a few sample virtual configs + the attached rules to the virtuals? Also, after removing the "RULE_INIT" event from your virtual, are you able to restart your tmm? You may need to restart tmm to make sure that the change takes affect in the tmm.
Thanks.