Section 56 2 vii b immovable property

Hi, I have purchased immovable property on 31.01.2014 which is less than market value and the difference amount is more than?50,000 and recently received notice from Department that difference amount will be taxable. Can anyone please suggest whether it is taxable or not?? Because It is applicable from 01.04.2014 as amended by finance act, 2013.