In the present work, a medium Mn, Fe–Mn–C–Al–Si alloy was subjected to different heat treatment conditions and subsequent deformation to understand the effect of these processes on austenite. It was found that, after intercritical annealing, the microstructure was ferrite plus austenite duplex phase (FADP) regardless of cooling rate to room temperature. When cold rolled, the retained austenite of the FADP structures exhibited both twinning and strain induced transformation (SIT) to martensite. A detailed characterization of the co-existence of twinning and SITing after cold rolling is presented.