Did your father die intestate(without leaving a WILL). If so, then all the legal heirs, i.e., Your mother and all your siblings will have equal share in the property. The procedure to transfer the title of the property in your mother's name would be to enclose your father's death certificate to the letter signed by all your siblings to the concerned authorities informing that the children have no objection to transfer the title of the property in their mother's name and request the revenue authorities to transfer the title from their father's name to mother's name.