Ngāti Hinemanu me Ngāti Paki chairman Jordan Winiata had been informed of the upcoming mandate hui, Potaka said.
"We are doing our best to include everyone. That's the key difference between our trust and theirs."
The voting will start on June 10, and end on July 8. It's being handled by Independent Election Services Ltd.
Potaka is keen to hear from everyone, even if they don't give mandate.
"If it's against the motion, that's fine. We need to hear that."
If the trust doesn't get mandate it would be "back to the drawing board", he said.
Tribes in the Taihape Inquiry Area will be some of the last in New Zealand to reach treaty settlement.
But they had spent the last 40 years developing hapū, iwi and marae and forming tribal representative bodies, Potaka said.
That focus will continue after settlement.