Where is transfer box relay location?
No relay - control module behind battery
If you are referencing a relatively new Range Rover up to 2012 model year, it does not have a Transfer Case relay in a physical sense. All T-case related functions are controlled by a Transfer Case Control Module. All functions once ran by a relay in older models (Say switching from low to high range) is now transistor controlled by the computer. I would suggest having the vehicle diagnosed by a technician using Symptom Driven Diagnostics (SDD) software to isolate whether the problem is Sensor, Switch wiring or actuator related.