I am trying to find-out % in the column level which should 4121/7975-52% similar to other also but somehow it is not working & showing 13%. Kindly help me out.
You will need to use a scope in the expression you are using to calculate the percentage. Month, in the example below, is the scope.
=Fields!qty.Value/Sum(Fields!qty.Value, "Month")
Since I don't have your RDL, you will need to determine what the scope name should be based on the group name for the months (Jan, Feb. etc.). This can get a little tricky, so you may have to try a few different scopes to get what you need. Chances are it will be whatever the name of the field is you are using for the month values. The group properties for that column will show the name, too.