insert into #tmp (CityID, CityName, TotalOrder)
Select distinct sr.RID as CityID,
sr.Rname as CityName
From #tmpID tid
Inner join StateRegions Sr on Sr.RID = tid.CityID
Group by Sr.RName,
sr.RID
Order by sr.RName
está intentando insertar 3 columnas en #tmp, pero la consulta solo devuelve 2 columnas
Sospecho que quieres Contar(*) o Suma(Pedidos) como la tercera columna