If a Muslim put his money in an interest-based bank, and he wanted to keep the principle and get rid of the interest, what in general are the places he could spend this money to give it away? Is it permissible to give this interest in charity to his family (brothers and sisters – parents – cousins)? Please advise and may Allah reward you well.

In the name of Allah, all praise is due to Allah, and may peace and blessing be upon the Messenger of Allah. To proceed:

You should get rid of this money by spending it on public facilities. It is permissible for you to give it to relatives in need as a way of getting rid of unlawful (haram) money, but you cannot give this money to your parents because providing for them is obligatory on you, so you cannot spend on them anything that it would not be permissible to spend on yourself. You must also transfer this money to an Islamic bank at the first opportunity to do so.