Your father needs help due to a disease and he signed a protection mandate in case of incapacity. Can we use his protection mandate in case of incapacity?

You can use the protection mandate in case of incapacity of your father when it will have been "homologated". It is about a procedure aiming to obtain a judgment noting the validity of the protection mandate in case of incapacity signed by your father and confirming his incapacity to administer his property and to take care of his person following a disease which impairs his physical and mental faculties.