I am not on a lease and deceased mother transferred title also large tax lien is active. What can I do to retain house?

Someone must be able to officially control and deal with the property.  Who owns the property?  If only your mother, was an estate opened for your mother and a personal representative appointed by the court?  If the lien is on the real estate, it will need to be satisfied if you want to retain the property.  That can come from the assets of your mother's estate.  If that's insufficient, then you'll likley have to pay the lien in order to retain the house.  Liens don't go away just becasue the property owner passes away.