you have first to check for the data like
SELECT COUNT(*) INTO XYZ FROM M_Meter,M_ServiceMaster,M_TOD where
TOD_Id = MTRM_TOD_Flag
and MTRM_Service_No = v_COM_Service_No
and SRM_Discon_tag_Id = 2
and SRM_Service_no = MTRM_Service_No and (MTRM_CHANGE_INDICATION=0 or MTRM_CHANGE_INDICATION is null);
IF XYZ > 0 THEN
return first cursor
ELSE
return second cursor
ENDIF;