T.I -- Rock Star Arrival to Atlanta Halfway House

Rapper T.I. -- along with a massive entourage -- arrived to an Atlanta halfway house where he'll kick it during the final month of his sentence.

T.I. made the trek from an Arkansas prison in a suped-up tour bus ... accompanied by a 4-car motorcade.

When T.I. got off the bus, he was sporting a striped polo shirt, shorts and a fancy watch.