i am trying to get value in Decimal in this query but unable to get i am getting NULL Value
SELECT CAST(CAST(CAST(SUM(CAST(0 AS INT)) AS DECIMAL(10, 2)) * 100
I don't even start to understand all the conversions that you are doing, but you can just simply use ISNULL on that expression:
ISNULL
SELECT ISNULL(,0)