Relinquishment deed

Dear Sir,

I am from Delhi, My father passed away in 2009. He has Power of Attorney of the House. After that me & my 2 sisters registered a relinquishment deed in my favor. My question is:-

1) As the property was on Power of attorney earlier, should I have to register in my name now & pay the stamp duty on today's circle rate?

2) OR Is the registered relinquishment deed is valid as well as a registered property.

3) I heard that no stamp duty has to pay because it comes to me from my father.

Please clarify.....

Thanks in advance!

Naveen