New Delhi, Sept. 21 -- The controversy surrounding the reappointment of N. Chandrasekaran as chairman of Tata Sons is larger than the tenure of one individual. It raises a fundamental question about the governance architecture of one of India's most consequential business institutions: who ultimately guards the Tata institution-the professional board, its controlling shareholder, Tata Trusts, or the regulator?

The timing makes the question particularly important. The Tata Sons board has approved another five-year term for Chandrasekaran, despite opposition from Tata Trusts chairman Noel Tata. At almost the same time, the Reserve Bank of India (RBI) has rejected Tata Sons' request to surrender its registration as a core investment company...