Product's price exceeding MRP due to tax

[veeran]

In Prestashop a product's price is exceeding its MRP, say a product is Rs.1000(MRP) it has 5%,10%,20% tax in 3 cities, when a customer order the product from 3rd city the products price becomes 1000 + 200 = 1200, where as MRP is only Rs.1100/-. I saw the code which is like price_tax_excl+tax=MRP instead of MRP-tax=price_tax_excl.Is there any alternative or any options available in Prestashop.Actually price exceeding mrp is not legal in INDIA.Help me to solve the problem.

Edited September 30, 2016 by veeran (see edit history)