What is the ruling on money earned by a father from working in an insurance company and spent on his family, and is it permissible for the father to give his children apartments, cars, and cash from this money?

Commercial insurance is forbidden in Islamic law because it involves gambling, Maysir (speculative transactions), and Gharar (excessive uncertainty). Working in it and the salary earned from it are also forbidden.

As for dealing with someone who possesses such money: If all his money comes from this forbidden job, then it is not permissible to engage in transactions with him, whether buying or selling, nor to accept his gift, nor to eat his food. For you, your siblings, and your mother, it is permissible to use this money only out of necessity and to the extent of what is essential for life (food, drink, clothing, housing, transportation). If you can do without it by obtaining other permissible money or work, then it is not permissible for you to use it. If his money is mixed with both lawful and unlawful sources, then it is permissible to deal with him.

It is advisable to counsel your father to leave this job.