The Resource Tycoon of Rebirth didn't mention the role of a yamen. However, according to the plot and background of the novel, we can guess that the son of a yamen may refer to the son of an official or a rich man. This was because the novel mentioned that the sons of some figures related to power and wealth, such as emperors, prime ministers, tycoons, etc., might also be called yamen. However, more information was needed to confirm the specific identity of the yamen.