I am not quite sure of the purport of your question: Do you mean to say your father owes interest money to the bank? If he does, you should pay it, if you have the financial resources; since they are debts he owes to others, as his children you should pay them off on his behalf.

 

If, however, you mean to ask: Your father has deposits in his account which have accrued interest, can you take it? The answer is: You should definitely do so rather than leaving it to the bank. You should take it and give it away to deserving people such as refugees or the destitute. It is not desirable for you to make use of such funds for your personal benefits.