Dear Rakel
As I know, there was no GID users in the telemac community (but it was before the free distribution).
I think the main problem will be in the file format of the mesh and/or the result.
Telemac use it's own file format (SELAFIN) for mesh and results and I suppose GID isn't able to read or write such files.
But the discussion is open and maybe someone could give us some new informations on this topic...
regards