Traumatic brain injury (TBI), is one of the leading causes of motor deficits in children and adults, affecting motor control, coordination, and acuity. This results in reduced functional ambulation and quality of life. Robotic exoskeletons (REs) are quickly becoming an effective method for gait neurorehabilitation in individuals with TBI. Neurorehabilitation is based on the principle that the human brain is capable of reorganization due to high dose motor training. Understanding the underlying mechanisms of cortical reorganization will help improve current rehabilitation. The objective of the study is to understand the cortical activity differences due to RE training and recovery of functional ambulation for individuals with chronic TBI, using functional near-infrared spectroscopy. There was an increase in cortical activation in the prefrontal cortex (PFC), bilateral premotor cortex (PMC) and motor cortex (M1) while walking with RE versus without RE at follow-up. Furthermore, decreased activation was observed in PFC, bilateral PMC and M1 from baseline to follow-up while walking without RE with a corresponding improvement in functional ambulation. These preliminary results for one participant provide initial evidence to understand the cortical mechanisms during RE gait training and the recovery induced due to the training.