Is it obligatory for the questioner to pay SAR 16,0 or INR 60,0 to his uncle, and is the money his uncle takes lawful for him, especially since his father refuses to pay and the questioner has started paying the amount without his father's knowledge?

This money falls into one of two categories: either it is a charity (sadaqah (definition)), in which case it is impermissible for your uncle to retract it, or it is a gift (hibah (definition)), in which case it is impermissible for him to retract it unless it was given with the intention of reward [from Allah].

If your uncle did not clarify his intention, then customary practice (urf) should be considered. If someone like him typically seeks reward [from Allah], then his statement, affirmed by his oath, is accepted. Otherwise, the statement of the recipient of the gift, affirmed by his oath, is accepted. If both interpretations are equally possible, then the statement of the donor, affirmed by his oath, is accepted.

In the event that the money must be returned, then sixty thousand Indonesian Rupiah or its equivalent in Saudi Riyals, at the exchange rate on the day of repayment, should be returned to him.