Low-profile detergent king, who delisted his company, Nirma, in 2012, returns to the list after a 4-year absence as a result of new information about the company's financial performance. Led by son Hiren, Nirma is expanding its cement business. In July the company beat bidders such as Ajay Piramal and the Jindal family's JSW Cement to buy French cement major Lafarge's India operations for $1.4 billion.