The agency won the business following a competitive pitch against agencies including TBWA, Y&R, McCann and BBDO held in Mumbai. The account will be led out of JWT London.
Tata has briefed the shop with creating a campaign that positions it as global, trustworthy and a good corporate citizen as it embarks on a global acquisition spree.
It will be the first brand campaign for the company and is due to break early next year.
Gustavo Martinez, the JWT global president, said: "This is one of the great corporate stories that deserves to be better known and understood across the globe.
"We look forward to harnessing JWT's expertise to make sure that global markets recognize the extremely successful values-driven organization that the Tata brand represents."
Tata owns the Land Rover and Tetley brands in the UK and their advertising accounts, held by Rainey Kelly Campbell Roalfe/Y&R and Creature respectively, are not affected by the appointment.