For all CD-based Sega games, Tec Toy merely did a new package and manual. The disc itself was just mass imported from USA.
For cartrigde games, I think that, back in the day, the ROM itself was also an US ROM. They only made a new plastic case and label.
So, if you buy a Tec Toy Saturn game, you *are* buying an US version, just with a cardboad box and a small portuguese manual.
Now, for the games developed/translated/modified by them... I'm not sure what they did. It's likely that they burned the cartridges themselves, since it's not that hard(after all, they continued to port GG games to the Master System themselves for ages).
The only CD-based game they touched was Saturn's Riven, that was fully translated and dubbed into portuguese. But I'm almost sure the game was pressed by an European company, and shipped over.