12dB for the BCCH TRX
9dB for a non-BCCH TRX.
Those are mean values used for planning.
I don’t really understand your questions. Let’s say that for voice, the voice quality in EFR is degraded when C/I < 9dB, whichever the TRX. But the TRX that carries the BCCH is more sensitive, so it is recommended to ensure the C/I never goes < 12dB.