You must use HEC-GeoRAS 10.8 . Versions designed for 10.7 or earlier will fail to register components.
HEC GeoRAS has a wide range of applications in hydraulic modeling, including: hec georas for arcgis 10.8
HEC-GeoRAS is a free ArcGIS extension that enables hydraulic engineers to process geospatial data through a graphical user interface. It consists of procedures, tools, and utilities for two primary functions: You must use HEC-GeoRAS 10
An important consideration for users is HEC's official support policy. . hec georas for arcgis 10.8