Hi.
Not quite sure about the maximum number of concurrent client connections that the wireless modem router can support since it is mainly restricted to router hardware and network environment.
For example, if some clients in your network are downloading large file, most of the bandwidth and system resources will be occupied, then only a few clients can enjoy the network, but if all the clients just do ordinary web browsing, then the router can handle much more clients simultaneously with good network performance.
Since wireless modem router is a Soho device, to ensure the smooth and flawless Internet connection, it is recommended to connect about 8-10 devices to the wireless modem router.