Radiated Immunity is synonymous with radiated susceptibility.  It is the ability of an electrical device to withstand radio frequency electromagnetic fields impinging on its enclosure, power leads, and interconnecting signal conductors.  Radiated Immunity is also, a term referring to EMI tests wherein the electrical device is subjected to electromagnetic fields impinging on its enclosure, power leads, and, interconnecting signal conductors. 

In EMI Analyst, radiated immunity is referred to as radiated susceptibility and is abbreviated, "RS".