Lachman Das Mittal, 93-year-old Chairman of tractor maker Sonalika Group, is India's oldest billionaire worth $2.9 billion, Forbes reported. An ex-LIC agent, Mittal started his business at age 60 after retiring from LIC. He used his savings to start a farm equipment business but it went bust, leaving him bankrupt, ET reported. Mittal started saving again and launched Sonalika Tractors.