Former Tata Sons director RK Krishnakumar passed away at the age of 84 in Mumbai on January 1. RK Krishna Kumar died of heart attack at his home at around 6 pm. Popularly known as ‘KK’, he was also a trustee of the Sir Dorabji Tata Trust and the Sir Ratan Tata Trust, which together hold a 66% stake in Tata Sons.