Senior executives of Adani, including founder and chairman Gautam Adani, discussed India's growing need for energy during the private meeting with the prime minister on Monday evening.
The company's $21.7 billion Carmichael coal mine project in Queensland was approved in December but has faced serious opposition from environmental and Indigenous groups.
Mr Adani requested an early resolution of native title issues surrounding the mine, which was hit by a Federal Court ruling that invalidated deals with traditional owners across Australia.
Legislation dealing with the problem is before the Senate and Mr Turnbull is understood to have assured the company the issue needed to be fixed and would be fixed.
Senior spokesman for the Wangan and Jagalingou Traditional Owners, Adrian Burragubba, said that the Government was selling out Traditional owners to meet the demands of mining interests.
"The Prime Minister is another in a long line of political leaders, Federal and State, who are willing to sacrifice Aboriginal peoples’ rights if a profit or a deal is attractive enough. It is extraordinary to have the Prime Minister travelling to India to tell a businessman that he will change the Native Title Act in Australia and undermine our rights so that his destructive project can proceed," he said.
“Mr Turnbull is selling out the country and the Australian people will be horrified that the Prime Minister is in India trading away our rights in an act of national betrayal."
“We call on Opposition Leader Bill Shorten to clarify if Labor has done a deal with the Government to support this sell out to Adani”, he said.
The Wangan and Jagalingou Traditional Owners have been fighting Indian mining giant, Adani, over a multi-billion dollar coalmine proposed to be built at the Galilee Basin, right in the heart of Wangan and Jagalingou country in central-west Queensland.
The federal government is considering a bid for a $1 billion concessional loan from its Northern Australia infrastructure fund to help build a rail line servicing the mine.
Ahead of the meeting, Mr Turnbull insisted a decision on the potential loan was going through an independent process.
It's understood Adani representatives mentioned the infrastructure fund during the meeting but made it clear they understood it was independent of the government.
The Greens are planning an attempt to block any government funding for the Carmichael mine or its railway line via legislation introducing a suitable person test for infrastructure fund applicants.
Environment spokeswoman Larissa Waters didn't believe Adani would pass the test.
"Overseas, Adani is under investigation for money laundering, fraud and corruption, including allegedly bribing public officials," she told AAP.
"They have ignored environmental laws causing irreversible damage."
Earlier on Monday, in a joint press appearance with Indian prime minister Narendra Modi, Mr Turnbull talked up the importance of Australian resources and expertise to the Indian energy sector.
"We're pleased to be providing increasing quantities of high quality coal for steel-making and increasingly for power generation with advanced supercritical technology," he told reporters.