If we talk about DSG the TCU is inside the Gearbox and often called "the motronic"
Golfs do have DQ250 (vag naming 02e) gearboxed or dq381.
Talking about DQ250 there is a cxx, exx and fxx version.
DQ250 cxx was inside "mk4 r32 dsg" too.
best option for flashing:
https://ecutools.eu/chip-tuning/pcmflash/module-58/depending on the stage1,2,3 of your engine you have to do to raise limiters and clutch pressure in the tcu.
