Please does anyone know at what mileage ( service interval ) the transmission fluid needs changing on 16my rrs hev

I believe JLR trot out the "sealed for life" mantra, which is total BS. Unless you accept a short life, that is.

Best practice, as I understand it, is oil and filter change every 50k miles.

Certainly that works for Jags, same 'box in effect. MY2016 HSE D SDV6 - gone due to fuel dilution problems.

By the age of 50 you have the face you deserve - George Orwell.

Thanks for the info, my car goes in tomorrow as LR approved used warranty ends @ he end of April and have been quoted £1200 for the service & transmition fluid change although the car has only covered 23500 miles from new.

Regards and thanks again for the info

If the fluid is being changed by an LR dealership using LR's technique, you're wasting your money. You'll pay for twice the required oil and not get the full job done. This is because just draining the box and refilling only changes a minority of the oil - most sits in the torque converter and is not touched by the "drain and refill". So they do it twice. But this still doesn't fully replace the oil.

Get it done by someone with a flush machine. This replaces as near to all the oil as you can get. Typically costs less than £300 all in. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Zf recommended at the 6 speed transmission of my BMW a change every 80000 - 120000km. Depending of the driving profile (towing etc.)

I did it with 112000km. They checked the logfiles of the transmission and deciced which "program" they will do. A flushing machine wan't used. The oil was drained and filled up.
They don't recommend a flushing in every case... Range Rover Sport HST D350