What is the ruling on depositing money in banks and taking only the principal, leaving the interest, and is it permissible to deduct bank charges from this left interest?

Deducting bank fees from usurious interest is not permissible. The basic principle is the impermissibility of depositing money in usurious banks, but it is permitted in cases of necessity and the absence of Islamic banks, provided the account is a current one that does not accrue interest. If this is not possible, and the interest is unavoidable, then it is obligatory to take it and dispose of it by giving it as charity to the poor or spending it for the benefit of Muslims, which is better than leaving it for the bank.