Reserved and mostly invisible to the public, Modi is viewed by many insiders and others in India’s business world as the right hand of billionaire Mukesh Ambani.

He has no flashy titles and few outside India know his name. But in the halls of Reliance Industries Ltd., Manoj Modi has quietly become one of the most powerful forces behind the corporate empire of Asia’s richest man.

Reserved and mostly invisible to the public, Modi is viewed by many insiders and others in India’s business world as the right hand of billionaire Mukesh Ambani. He played a key role during negotiations for a $5.7 billion deal with Facebook Inc. in April, backing Ambani and his children as they hashed out an agreement with the social networking giant, people familiar with the matter said.

As Ambani, 63, shifts his sprawling conglomerate’s focus from petrochemicals to internet technologies, Modi is seen as a particularly influential voice. Facebook’s investment in the group’s Jio Platforms was followed by similar deals from a slew of private-equity funds, injecting $13 billion into the business and placing it firmly on Silicon Valley’s radar.

The sixty-something, diminutive Modi — who isn’t related to India’s Prime Minister Narendra Modi — rarely gives interviews and there’s little in the public realm about his private life. Yet he illustrates how lesser known personalities in India with long-running ties to corporate dynasties can have an out sized impact.

“It’s not a company that advertises its organizational structure but the industry knows that Ambani and Modi are a strongly-bonded team — and together drive deal negotiation and relentless execution to the last level of detail,” said Vani Kola, managing director of venture capital firm, Kalaari Capital Partners, who persuaded Modi to make a rare public appearance at a conference last year, albeit by video.

But then came a hint of his thinking: “Our principle at Reliance is very simple: Unless everyone makes money while working with us, you cannot have a sustainable business.”

In interviews, more than half-a-dozen executives in the technology industry, who have had dealings with Reliance, said Modi has a reputation for driving hard bargains. When dealing with startups, he often controls negotiations from behind the scenes by instructing executives how far to push, making an appearance nearing deal fruition, they said