Finally I figured out this problem. But I had to use MSStackedColumn2DLineDY chart instead of 3D one that I was using. However I would like to customize the look of the graph especially I would like to remove the white gradient. Is there any way to remove the gradient. I tried all this but it did not worked.
"dataset":
[{
"dataset":
[{
"seriesname": "Clicks",
"showvalues": "0",
"data": clickData
},{
"seriesname": "Sales",
"color" : "8BBA00",
"plotfillratio":"100",
"plotFillAlpha":"100",
"plotgradientcolor":"009933",
"showvalues": "1",
"data": salesData
}]
}]