Dakhil- kharij (mutation) and change of title in plot registry

My father had purchased a plot in 1999 (as per Title deed dated 04-01-1999) in Disstt. Ghaziabad (UP). He died in year 2009. I am quite not sure whether he had got Mutation commonly known as DAKHIL KHARIJ of the said plot or not. As far as the official site of land records in UP (i.e. BHULKH) concerned the property is still showing in the name of the person from whom my father had purchased the plot. Now, I want to transfer the ownership of the plot in my mother’s name and got mutation DAKHIL KHARIJ, if not done earlier (i.e. want to make proper documentation). Kindly suggest the proper way or procedure to do the same.