Complaints and submissions from serving defence personnel have surged after a scathing report by a royal canin tavuklu kedi maması commission into suicide among Australia's armed forces.

Opening a seventh block of public hearings, commissioner Nick Kaldas said the overwhelming response to the Royal Commission into Defence and Veteran Suicide interim report in August had lifted the number of submissions to more than 2500.

Mr Kaldas told the inquiry in Darwin that the response had been bolstered by public assurances from Chief of the Defence Force Angus Campbell that no serving member would be penalised for speaking to the inquiry.

"We're grateful to everyone who has had the strength and courage to share their story with us," the commissioner said.

The seven days of public hearings in the Northern Territory will primarily focus on issues such as training and mental health support at Larrakeyah Barracks and HMAS Coonawarra in Darwin as well as RAAF Base Tindal, near Katherine.

Counsel assisting Peter Singleton said while the commission would focus on a range of issues, there were unique challenges in the region given the remote locations of the NT bases.

Mr Singleton said risk factors associated with deployment would be a major focus, including the potential for exposure to traumatic events and situations of extreme stress and isolation from family and support networks.

He said the commission would hear about the challenges of working in the NT and the systemic barriers that existed in delivering effective mental health support to current and former ADF members.

A number of lived-experience witnesses are expected to give evidence next week, including John and Robyn Halloran, the parents of 21-year-old private Thomas Halloran, who died by suicide on 26 April at Robertson Barracks in Darwin.

Mr Singleton said Mr Halloran "was known for his big smile, quick wit, and generosity".

The inquiry heard his parents were "still very much in the process of recovering from the shock and pain of their indescribable loss".

"We thank them for their courage in coming forward and giving so much to this commission at such a difficult time," Mr Singleton said.

The commission's 300-page interim report, publicly released in August, flagged the inquiry's dismay at the uncaring culture and inadequate support services in defence and veterans affairs.

The Albanese government responded to the report last month, with Veterans' Affairs Minister Matt Keogh issuing an apology in parliament.

He said the government would act immediately on the two most critical recommendations of simplifying complex veteran compensation legislation and ending the backlog of veteran compensation claims.

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