@Pimania 

In general, TP-Link routers support multicast from the internal network (LAN), but support for specific features depends on the model (Home vs. Business grade devices) and configuration. They typically support IGMP Snooping and Multicast Forwarding to manage traffic efficiently within the LAN:

• IGMP Snooping: Most TP-Link routers (including Archer and Deco models) support IGMP snooping. This allows them to listen to IGMP reports from clients to ensure multicast traffic is only sent to the devices that requested it, rather than broadcasting it to the entire network.
• Wireless Multicast Forwarding (WMF): Many TP-Link home routers have a setting (often under Advanced > Network > IPTV/VLAN) called "Wireless Multicast Forwarding" or "Enable IGMP" that must be activated for devices like IP cameras, Sonos speakers, or IPTV boxes to receive multicast streams over Wi-Fi.