Ousted Tata Sons Ltd. Chairman Cyrus Mistry resigned as director of group companies on the eve of shareholder meetings to remove him and pledged to take the fight with the scion of the $100 billion conglomerate to a “larger platform.” Mistry stepped down as a director in Tata Steel Ltd., Tata Chemicals Ltd., Tata Global Beverages Ltd. and Indian Hotels Co., and as chairman of Tata Motors Ltd., the five companies said in stock exchange filings.