For Kerry Broadband (like most fibre or wireless broadband services), you don’t need a special brand router, but your router must support a few basic things:
You need a standard broadband router with Ethernet WAN port (this is important), because the internet comes from an ONT or outdoor receiver into your home via Ethernet cable. The router should support PPPoE or Dynamic IP (DHCP) depending on your connection setup, and ideally it should support dual-band WiFi (2.4GHz + 5GHz) for better speed and coverage. For higher-speed fibre packages, a Gigabit (1Gbps) router is recommended so you don’t lose speed.
In simple words: any good quality modern router (like TP-Link, Netgear, ASUS, etc.) that supports Ethernet WAN will work fine — no need for a special Kerry Broadband-branded router unless they provide one themselves.