RaLinkClient is a Router Chipset app used by many brands already. It will be shown because there’s another wireless configuration in your area that is using the same address range as your router – this will cause it to pass filtering and show up as part of your network. This typically happens with routers that are working with the default IP address range. There's nothing to worry about! And just to mention, there's also the possibility that RaLinkClient is used on Smart TVs and shows up on the PC because that Smart Tv is connected to the PC by WiFi!