Postbank Systems has around 1,500 employees, mainly in the German city of Bonn. The sale is part of Deutsche's plan to shed 18,000 staff overall to cut costs and restore profitability.
Deutsche Bank will pay TCS's integration costs of 120 million euros ($142.69 million) as part of the deal.
"As part of our move to one technology organisation, we are consolidating the IT platform for our retail banking brand Postbank into the Deutsche Bank platform," Deutsche Bank's Chief Technology Officer Bernd Leukert said.
TCS is already an IT services partner for Deutsche Bank and the acquisition will add to TCS's capabilities in the banking domain", N. G. Subramaniam, Chief Operating Officer and Executive Director, said.
($1 = 0.8410 euros)
(Reporting by Arno Schuetze and Patricia Uhlig; Editing by Michelle Adair)