Is it permissible for an unemployed young man, who is supported by his father, to spend the money given to him by his father for Eid clothes on paying off debts, seeing that as more beneficial for him?

If the father stipulates to his son that he must purchase clothes for a specific amount, then the condition must be adhered to; this is based on the Prophet's (peace and blessings be upon him) saying: "Muslims are bound by their conditions." However, if he does not stipulate anything, and his intention is to fulfill his son's need, then the son may dispose of the money as he wishes, provided it is permissible.