He was the chairman of Tata Group , a Mumbai - based business conglomerate from 1991 till 2012 , and continues to head it 's charitable trusts .
He was the chairman of Tata Group , a Mumbai - based business conglomerate from 1991 -- 2012 . 
 He stepped down as the chairman of the group , on 28 December 2012 but continues to head it 's charitable trusts .