Is it permissible to call the two daughters by other names while their names, "Rama" and "Bisan," remain on official documents, this being after the father learned that naming them with these is impermissible and it is difficult to officially change the names?

It is obligatory to name children with good names that have virtuous meanings. The name "Bisan" is not preferred, but it is not religiously forbidden, especially if it is common in the country. As for the name "Rama," it is not permissible to use it because it is the name of a Hindu deity, and it must be changed officially and in address. It is also recommended to change the name "Bisan" if possible.