Now instead of Date and time conversion..I tried following:

SUBSTRING(LTRIM(RTRIM([Date])),LEN(LTRIM(RTRIM([Date]))) - 3,LEN(LTRIM(RTRIM([Date])))) + "-" + SUBSTRING(LTRIM(RTRIM([Date])),1,FINDSTRING(LTRIM(RTRIM([Date])),"/",1) - 1) + "-" + SUBSTRING(LTRIM(RTRIM([Date])),FINDSTRING(LTRIM(RTRIM([Date])),"/",1) + 1,2)+" 00:00:00.000"

STILL NOT WORKING 🙁