Originally Posted by
HTupolev
Shimano still produces a named 6-speed group under their mountain lineup, Tourney TZ.
To be realistic, they classify the below-Deore as hybrid/trekking class. Deore and above is classified as MTB. Deore and higher have clutches, and all the brakes have compatible hoses etc. So Deore is the bottom of what you want if it is off-road.