An intense boardroom battle is brewing at India's giant Tata Group

An intense boardroom dispute is brewing for control of Tata Group, the Indian multinational conglomerate that owns Jaguar Land Rover and Air India, and is a key supplier for Apple.

On Thursday, Noel Tata, the heir of the Tata family and the chair of Tata Trusts, said that the reappointment of N. Chandrasekaran as the chairman of Tata Sons earlier in the day was "illegal."

Noel Tata wants to keep Tata Sons private to safeguard its current ownership, experts said, while Chandrasekaran wants to grow the business by making large, bold bets that require massive capital.

If the dispute lasts beyond six months, as happened 10 years ago , it may delay the prospective listing of Tata Sons — a crucial part of Chandrasekaran's strategy to get the funding he needs.