Narendra,
,You can use any Discount Condition Type for reducing 14 % Tax amount in your Sales Order Manually or automatically .
By reading your suggestion once I could not understand the point.
Are you saying create another condition type, which shall be 14% minus. In other words would make the tax component zero (in the sales order)?
If yes, then what about the amount posted to tax? (i.e. 14%)
In the accounting view, it would still be seen as the tax was 14% (value equivalent to 14%).
That is not the case. Here if the customer is of a select Customer group, then the tax = zero.