What is the ruling concerning the garment brought by the brother from his travel, and is it permissible to wear it, knowing that another brother gave a second garment to the uncle without the knowledge of the first?

It is permissible for the uncle to wear the garment given to him as a gift by his brother, and he may dispose of it as he wishes, because the basic rule regarding gifts is that it is desirable to accept them unless there is a legitimate impediment. Indeed, the Prophet, peace and blessings be upon him, used to accept gifts. However, if the garment did not reach the uncle, and the brother exchanged it for another garment, then this is an infringement and the brother is not permitted to do so, because it is obligatory for the one entrusted with giving something to do what he was commanded.