SELECT XMLELEment("firms",
                      XMLAGG(XMLELEMENT("firm",
                                        XMLELEMENT("FirmID", wo.id),
                                        XMLELEMENT("Name",
                                                   substr(wo.namerus, 1, 120)),
                                        XMLELEMENT("ShortName", wo.code)           
                                                   )))
      into my_var
      FROM organs wo
     where type_id = 5;
  
    --Выводим в вывод
    dbms_output.put_line(my_var.GetClobVal());