The company today has its hand in almost every business imaginable, from consulting to automobiles. Ratan Tata, the cousin of his predecessor, took over the company in 1991 at the age of 53. He became the group’s fifth chairman. He widened the group’s international presence, acquiring Corus Group, the Anglo-Dutch steel company, in 2007 and the Jaguar and Land Rover brands in 2008.

Mr. Mistry — the first non-Tata family member to lead the nearly 150-year-old company — was elevated in 2012 after a two-year search. However, in India’s tight-knit Parsi community, the ties can be close. Mr. Mistry’s family, which owns a major construction business, was the biggest shareholder in Tata Sons, with 18 percent, and Mr. Mistry had been on the board since 2006. His sister is married to Mr. Tata’s half brother.

According to several people close to Mr. Mistry, the relationship between him and Mr. Tata soured in part because Mr. Mistry had begun reining in some favors that the company had previously extended to Mr. Tata’s personal friends.

In one instance, after Mr. Mistry raised the issue, the Tata board explored starting legal proceedings against C. Sivasankaran, a longtime friend and close business associate of Mr. Tata’s, to try to recover $100 million the company said it was owed from a telecom deal. Mr. Sivasankaran also had been renting a 5,300-square-foot penthouse for $11,000, less than half the market rent, from the company, according to correspondence reviewed by The Times. Mr. Mistry raised his rent to the market rate.

Mr. Sivasankaran, in an interview, said he was indeed a friend of Mr. Tata’s. He said, though, that he had suffered financially from the investment and had no intention of paying back the $100 million he owed.

“I don’t want to pay it because Tata has not managed the company properly,” he said. “Siva is alleging the Tata Group does not have management skills,” Mr. Sivasankaran said, referring to himself in the third person.

He also confirmed that he was ousted from the luxury apartment. Mr. Sivasankaran said he had a long-term contract to stay there, so he could have fought to stay, but decided to go quietly.