Hello,
There is no version of SUBIEF with license any more for sure, nor actual version: I think that the sources have not changed since 5 years or more but should not be compatible with an actual version of TELEMAC. It would be very tricky to use old codes.
Anyway, you must be able to implement your own water quality model with tracers in TELEMAC (2D or 3D) or you can use the DELWAQ model from Deltares that is now available in open source.
Maybe you can try to ask to your previous supplier of SUBIEF and see what it can do for you.
Hope this helps,
Chi-Tuan