The two iwi groups see the deal as potentially rejuvenating a region which has the country's second-lowest median income after Northland.
"We see this as being part of building new communities," Mr Wawatai said.
Turanganui-a-Kiwa chief executive Ron Nepe said both iwi already provided health and social services to many tenants and had marae connections to many families.
"We can add value to the families in those houses and give them other options besides being tenants, help them into affordable home ownership," he said.
Maori make up 61 per cent of Housing New Zealand tenants in the region stretching from Waikato to Hawkes Bay, but Mr Wawatai said iwi were keen to take on Pakeha tenants, too.
"We deliver health services to everyone in our region," he said.
But he said the Government also needed to retain some responsibility.
"Our concern would be about social housing, not welfare housing," he said.
"A lot of the current clients of Housing NZ, we would need to have a discussion with the Crown as to what is the future of those tenancies with respect to the obligations that the Crown might retain."
Ngati Porou received $110 million from the Government in 2012 to settle its claims under the Treaty of Waitangi, and Mr Wawatai said another partner would help finance the deal.
"We are ready," he said. "We are a long way ahead of most other iwi."
Gisborne Mayor Meng Foon supports the iwi bid.
"I think they will be a better landlord than the state. They are inter-generational, they want to look after their people and the community," he said.
Kaiti state house tenant Dave Willis, 64, said he would not be too happy to have his house "sold underneath me", but he felt Housing New Zealand had not maintained his house well and that iwi might do better.
"Anything's worth a try," he said.
"I don't know whether it would be better or not."