Urgent query

My Uncle have got some balance dollars, which he had exchanged at Airport while travelling to USA 3 years back. Now he wants to convert those balance dollars into INR. The money changer is quoting 3 different rates:- 1) Exchange with old currency notes 2) Exchange by Cheque 3) Exchange by new currency notes, the highest quote being exchange with old currency notes. If he converts in old currency notes will he get taxed as per new government regulations????