Tata Sons has also issued a special notice under Section 169 (read with Section 115) of the Companies Act, 2013, and made a requisition for an extraordinary general meeting of shareholders to consider the removal of Mistry as a director of TCS.
"Hussain shall hold office as Chairman of the company until a new chairman is appointed in his place," the company said in a regulatory filing.
Tata Sons had removed Mistry, 48, as chairman of Tata Sons last month saying he had lost the confidence of the board due to several factors and that the trustees were increasingly concerned with the growing trust deficit.
Ratan Tata, who had made room for Mistry four years ago, was reinstated as the chair in an interim capacity.
Hussain, 69, took over as director finance of Tata Sons in July 2000. Earlier, he joined the board as an executive director in July 1999. He is also a director of several Tata firms -- Tata Industries, Tata Steel and Voltas. Besides, he is the chairman of Voltas and Tata Sky.
Prior to joining Tata Sons, Hussain was senior vice president and executive director of finance at Tata Steel for almost 10 years. He joined the board of the Indian Tube Company (a Tata Steel associate) in 1981 and moved to Tata Steel in 1983 after the company was merged with Tata Steel.
A chartered accountant by training from Institute of Chartered Accountants in England and Wales, he graduated in economics from St. Stephens College in New Delhi