If I’m not wrong you have the following (unsure of the name of each axis):
standard axis for up/down, i.e. the axis all normal strokers use
pitch, axis for how the sleeve lean left or right,
roll, axis for how the sleeve lean forward or backward,
twist, axis for how the sleeve is rotated
sway, axis for how far the sleeve is from you (typically to script grinding)
surge, axis for how the sleeve moves left or right
So basically, 3 axis for movement and 3 for rotation.
Have a look at the protocol documentation for a picture:
https://stpihkal.docs.buttplug.io/protocols/tcode.html#multi-axis-devices