It depends what you goal is. If you were to run QoS WITHIN your house you might get the router to control it..hard to say it really depends on the router and its abilities. Still QoS only matters when you have a bottleneck. Inside your house there is so much capacity that the router seldom would need to even decide who goes first. It is not going to delay traffic if there is no need.
If you are talking internet then only the device connected to the line can do any form of QoS. For most routers you are limited to controlling data being SENT..ie upload. You seldom overload your upload link. Most issues are in the traffic coming to your house ie download. There is only limited things you can do the ISP is in full control and...