Ratan Tata, the Chairman Emeritus of Tata Sons, has invested an undisclosed sum in Gurgaon-based cashback and coupons website CashKaro.com. This is Ratan Tata's third investment of 2016. Founded in 2013 by Swati and Rohan Bhargava, the startup raised about $3.7 million in Series A funding led by Kalaari Capital in November last year.