Hi Rahul Goja....
Try this
/* select * from oinm t1 */
DECLARE @D1 DATETIME
DECLARE @D2 DATETIME
DECLARE @D3 NVARCHAR(100)
SET @D1=/* t1.DocDATE */ '[%1]'
SET @D2=/* t1.DocDATE */ '[%2]'
SET @D3=/* T1.itemcode */ '[%3]'
SELECT x.Month As Month, X.CODE , sum(X.Grpo)As Grpo , Sum(x.Prodissue)As Production,Diff=(sum(X.Grpo) - Sum(x.Prodissue)) FROM (
SELECT month(t1.DocDate) As Month , T1.ITEMCODE aS coDE,
CASE WHEN TransType='20' THEN SUM(T1.INQTY) ELSE '0' END AS grpo,'0' aS Prodissue
FROM OINM T1
WHERE TransType='20' and t1.DocDate between @D1 and @D2 and t1.ItemCode=@d3
GROUP BY T1.ITEMCODE,TransType,month(t1.DocDate)
UNION ALL
SELECT month(t1.DocDate) As Month , T1.ITEMCODE,'0',
CASE WHEN TransType='60' THEN SUM(T1.OUTQTY) ELSE '0' END AS Prodissue
FROM OINM T1
WHERE TransType='60' and t1.applobj='202' and t1.DocDate between @D1 and @D2 and t1.ItemCode=@d3
GROUP BY T1.ITEMCODE,TransType,month(t1.DocDate)
) AS X
group by X.CODE,x.Month
Hope helpful 
Regards
Kennedy