1. According to the partition deed that was executed, the property was divided between your father, brother and yourself, which means that each of the three had a 1/3rd share in the property.
2. Since the property in question was the self acquired property of your father he was at liberty during his life time to make any instrument of disposition of property and distribute his property in the manner he desired. Consequently, your sisters and brother, who were not given any share in the property, have no right to claim a share now. In this view of the matter, no NOC is required from your sisters.
3. However, if your father did not leave behind a will as to his share in the property then his widow and all his children succeeded equally to his share. The daughters can enforce their share by moving to court and filing for partition.
4. It is prudent on the part of the bank to have asked you for a NOC from your sisters in so far as your sisters also have an indefeasible share in the property.
5. You can either purchase the share of your sisters or enter into a family settlement with them.