Epic TV is a niche high-definition channel, which will have content based on the nation's history, folklore and mythology in a contemporary format.
Set up last October, Epic Television Network is being led by Mahesh Samat, former managing director of Walt Disney Company, who had left the US major last year after a four-year stint.
While refusing to offer details, a Reliance Industries spokesperson confirmed the development and said the investment by Mr. Ambani is "in his personal capacity".
According to reports, Mr. Ambani holds over 25 per cent stake along with Mr. Mahindra. The investment is routed through Reliance Ports & Terminals, which is one of Mr. Ambani's personal firms.
Mr. Samat had earlier said Epic TV was being funded by a group of angel investors but declined to name the investors or the amount.
Epic TV will be Mr. Ambani's second broadcasting venture as he already owns a considerable stake in the Network18 Group.
In January 2012, a shell company floated by Mr. Ambani had agreed to invest close to Rs 2,000 crore in Raghav Bahl-promoted debt-ridden media companies Network 18 and TV18 Broadcast, which runs channels like CNBC TV18, CNN-IBN, and Colors among others.
The Network18 deal came after Reliance decided to exit a large part of its investment in ETV channels, which was to be acquired by TV18 Broadcast for Rs 2,100 crore. In 2008, RIL had invested Rs 2,600 crore in Ushodaya Enterprises, the holding company of the ETV channels through JM Financials.
The new channel aims to tap into the now digitized cable TV ecosystem and the DTH platform to take advantage of the growing opportunities.
It will have about 4-5 hrs of fresh programming every day, which will include 2-3 hrs of long programming and 1-2 hrs of narrative non-fiction shows.
Set up in 1997, Reliance Ports & Terminals, which is engaged in storage, handling and evacuation of crude oil and petroleum products, had in 2008 merged nine group companies with itself to consolidate the Reliance Group's logistics, engineering and construction-related services businesses.
Of the merged firms, four provide logistics, pipeline and engineering-related services to the parent company Reliance, while the others are investment-holding companies.
The Jamnagar-based company also handles petroleum product evaluation for the group's Jamnagar refinery.