It can be all sorts of things apparently but in my experience with a few different batches that have come in to the dealers as "tuci" not made by them has been that it is mostly ketamine with a small amount of MDMA and dyed pink with food colouring.
It is not 2cb, I think it is meant to mimic the effects of 2cb but has never been that.
Last year it was becoming fairly popular in Australia but I haven't seen it in awhile.
I'm actually surprised at how popular it was considering it is essentially a drug that no-one really knows exactly what they are ingesting.
I only tried it a few times and it was pretty weak. I was high on meth and maybe GBL the first time so that probably masked the effects but the batch I tried was pretty average (actually it was just shit!)
I wouldn't try it again unless it was free coz if I want MDMA mixed with ket or I want 2cb then I will just use that.
It was fairly expensive too, more so than what it would cost me to make myself so yeah, screw that!