Keane, who has been a prolific scorer playing for Republic of Ireland with 146 International appearances scoring 68 goals, will be strengthening the new look ATK side.
"I feel extremely fortunate to have played for some of the best clubs in England and the USA, as well as representing my country at several major tournaments," said Keane, who has been Ireland's top scorer at the 2002 FIFA World Cup and also played at UEFA Euro 2012 followed by Euro 2016.
Robbie has been one of the legends of English Premier League football, leaving his legacy with clubs like Tottenham Hotspur, Liverpool and Major League Soccer team Los Angeles Galaxy.
A talented, quick, and agile player, Keane is a versatile forward, capable of playing anywhere along the front line always searching to net those memorable goals.
"As a football fan I am eagerly looking forward to some Irish magic touch on the field when Robbie plays his first game in our colours," said Sanjiv Goenka, Chairman RP-Sanjiv Goenka Group, Principal Owner, ATK.