Prime Minister Malcolm Turnbull announced the inquiry fewer than 12 hours after shocking footage of boys being tear gassed at the Don Dale Youth Detention Centre was aired on national television.
Northern Land Council chief executive Joe Morrison has serious reservations about the prospect of any real change coming out of the probe, given the "impossibly short" reporting time.
Mr Morrison said 25 days have been set aside for formal hearings which would make it one of the speediest inquiries in recent history.
There are fears it may not be possible to hand down a report by the end of March next year and Mr Morrison is calling for an extension to the "overly ambitious" deadline.
"There's concerns it will end up being just another opportunity to have a talkfest and a bit of a yack," he told ABC Radio.
"We need to get to the root causes of why so many of our young kids are getting incarcerated."
Mr Morrison said the NT and commonwealth governments are dedicating $50 million for the royal commission, but this should also be reviewed.
"Much more investigative work needs to be done, and Aboriginal people from remote areas need to be able to contribute."
"There are some serious issues that need to be dealt with and we don't want to see it as a missed opportunity," Mr Morrison said.