6G eXperimental research infRastructure to enable next-generation XR services (6G-XR) will develop an evolvable experimental infrastructure for the duration of the SNS programme that covers demonstrating the performance of key B5G/6G candidate technologies, components, and architectures to keep the infrastuctures valid now, in mid-term and in long-term. It will demonstrate technological feasibility of “better than 5G” KPIs, innovative radio spectrum technologies and the use and sharing applicable to beyond 5G and 6G spectrum, validate a representative end-to-end beyond 5G architecture (and later 6G) including end-to-end service provisioning with slicing capabilities, and at cloud implementation level (Open RAN). Furthermore, 6G-XR shall validate multi access edge computing scenarios and their integration into a complete cloud continuum, support innovative use cases with vertical actors, beyond 5G capabilities, and support showcasing events. In addition, 6G-XR demonstrates and validates performance of innovative 6G applications with a focus on demanding immersive applications such as holographics, digital twins and XR/VR. 6G-XR will support impactful contribution to standards and demonstrate the technological feasibility of key societal requirements and objectives such as energy reduction at both platform and network levels.