Remove ORRMCTG column from your query and you'll get desired results.
SELECT OMTC
,OMYY
,OMNO
,ODSR
,OMCMCD
,OMLMGCST
,ODSALPRC
,SUM(ORSALVAL) as total
FROM ORDMST
INNER JOIN ORDDSG ON OMTC=ODTC AND OMYY=ODYY AND OMCHR=ODCHR AND OMNO=ODNO
INNER JOIN ORDRM ON ODTC=ORTC AND ODYY=ORYY AND ODCHR=ORCHR AND ODNO=ORNO AND ODSR=ORSR
WHERE omtc='qt' AND omyy='13' AND omchr='KPS' AND omno='174' AND ODSR=2
AND ORRMCTG NOT IN ('d','C')
GROUP BY ODSR,OMTC,OMYY,OMNO,OMCMCD,OMLMGCST,ODSALPRC