Notwithstanding anything contained in the Wealth-tax Act, 1957 (27 of 1957), the Income-tax Act, 1961 (43 of 1961), or any other enactment for the time being in force relating to tax on wealth, income, profits or gains, the Authority shall not be liable to pay wealth-tax, income-tax or any other tax in respect of their wealth, income, profits or gains derived.