The primary goal of GeoRAS is to create a geometric import file for HEC-RAS. Hydrologic Engineering Center (.mil) HEC-GeoRAS Users Manual - Hydrologic Engineering Center
Reset ArcMap UI. Delete C:\Users\[YourName]\AppData\Roaming\ESRI\Desktop10.8\ArcMap\Normal.mxt . Then re-add the toolbar. hec georas for arcgis 108 upd