Is a father sinful for registering the apartment he lives in under the names of his daughters to prevent problems with his brothers, and the other apartment under the name of his wife? And do his brothers inherit from both apartments or only from the inherited apartment?

A man's gift to his wife and daughters is permissible if it is for their needs, or out of kindness to them, or to reward them for their help, provided that the intention is not to deprive the heirs of their rightful share. There is no difference in this regard between inherited and acquired properties.