First question is why bother with such a old worthless car ?

You have stated your car is 1999 Clio II
This will make it a PHASE 1 ( radio Ariel at front of roof )

Your car will have a BMT and not a UCH.
BMT and UCH are very different and share nothing in common.

CLIO II (phase II) 2001 on (Ariel at rear of roof) is a completely different immobilizer system.

The Reason you can find any functions for BMT on CLIP is because it was never there to start with.

BMT is on XR25 Only (Renaults diagnostic machine pre clip )
The chances of finding someone with a working XR25 is now very remote.

the choice is scrap it or modify the engine ECU with IMMO off or running a RPM module.

I Forget to say The info from Carl is for UCH, so not applicable for your car.