Sale of property [flat]

Hi,

We are in the process of selling our house [flat] which is registered in mine, my father & mother's name. My father is no more. We bought this property by applying for a loan [it is not inhertied by my father]. I had borne about 80% of the cost [by the way of repaying the loan].

I have 2 sisters who are married & settled abroad [they are citizens of that country and hold PIO card].

So when I sell this flat, do I need to take NoC or any other clearance from my sisters? If so can you tell me the procedure and document formats?

Thanks.