By GEETA ANANDDEC. 17, 2016, NYTimes.com

MUMBAI, India — In India, where corruption is a fact of life, the Tata Group — a powerhouse conglomerate that makes Land Rovers, operates the historic Pierre Hotel in New York and sells the world Tetley tea — has been held up as the exception to the rule.

Its patriarch, Ratan Tata, 78, is a revered figure here, a cross between Warren E. Buffett and Bill Gates whom even schoolchildren know and look up to as Mr. Clean — the billionaire whose family built its name in part on zero tolerance for corruption.

His company symbolizes the role an ascendant India sees for itself on the global stage. In 2010 Mr. Tata arranged a $50 million donation to the Harvard Business School, the school’s largest gift from an international donor, and its dean sits on the board of the empire’s umbrella organization, Tata Sons. Mr. Tata has been knighted by Queen Elizabeth.

Now, however, Mr. Tata is caught up in a nasty public fight for control of the business — with the man he had chosen to succeed him as chairman. The company finds itself defending against serious allegations of wrongdoing.