Ambani, who is chairman of the oil and gas conglomerate Reliance Industries Ltd, was in talks with Network18 with a view to acquiring a minority stake, the Wall Street Journal said, quoting people familiar with the matter.
Shares in the Network18 group, which runs television stations like CNBC and MTV plus e-commerce sites, jumped as much as 19.92 percent to 43.35 on the Bombay Stock Exchange.
It fell back in morning trade but was still up more than 16 percent.
Any deal could give Network18 a much-needed boost as it battles to claw back a net loss of 691.3 million rupees ($13 million) in its last financial year.
No one was immediately available for comment when contacted by AFP but a Reliance spokesman told the Wall Street Journal that the company did not comment on market speculation.
Reliance, which is India’s largest private sector firm, has been looking to diversify its portfolio in recent months in areas from communications to hotels and has been linked to several possible deals.
Last year, it announced a re-entry into the telecom and broadband segment after a five year absence by acquiring Infotel Broadband, which was the only firm to win an India-wide licence for fourth-generation broadband wireless services.
Mukesh Ambani’s younger brother, Anil, who heads the Reliance Anil Dhirubhai Ambani Group, has interests in media, film and entertainment through his Reliance Entertainment unit.
The brothers fell out over the spoils of their father’s vast business empire when he died in 2002 without leaving a will, but later agreed not to encroach on the other’s area of business.