There are no "true" Garand carbines aka "Tankers" in the private market.
Garand and Springfield experimented with a short 18" barreled Carbine version with a folding stock (the M1E5) and a carbine 18" barreled with standard stock (the T26)
There was a high demand for a more mobile service rifle at the time of WWII in the Pacific theater. Which resulted in a lot of testing and chop jobs by front line soldiers and apparently weapon techs, samples sent back to the U.S. and even some factory production of some 18" barrels but they never went into mass production. They say a few did actually see service use near the end of the war but I've never seen proof and these were probably the hack job "in theater" cut downs.
From what I read, the U.S. Proving/design teams could never get the weapon to cycle or function reliably with the short barrel while still performing to a high enough standard as a battle rifle.
Any short barreled Garand you find in this country with a less than 18.5" barrel would just be some hack job impersonation of a the experimental T26 and would result in it being a restricted firearm.
The more recent "reproductions" from the U.S. are actually 18.25" barreled if I'm not mistaken, which would make them restricted up here if any ever were imported.
That being said you may find M1's up here in Canada with chopped down barrels and gas systems to 18.5" with modified stocks, maybe even done by competent gunsmiths.
Seeing some of the monstrosities that people create in their sheds out of other great rifles would lead me to believe it has been done for sure 