Stamp Duty on Relinquishment Deed

My father has one house in which we live. He has expired in Mar'19. He had power of attonery in his name which we transferred to my mother's name through reliquishment deed in Apr'19. I just applied for mutuation of our home. But one person from revenue department came and asked us to calculate Cirecle Rate of our home and pay Stamp Duty for transferring home in my mother's name. We told that we have made reqliuishement deed and paid Rs. 100 as stamp duty. He denied and asked to pay 6% Stamp duty on circle rate. My question is that whether we have to pay Stamp duty on Reliquishemtn deed or not?? Can we get any legal notice from revenue department for not paying stamp duty???? Please advise. Thanks