I don’t have any VHS-c or anything to play them so I can’t do any testing.
From what I’ve read about them most are from camcorders so shouldn’t be copy protected.
So first are these “home movies” or something commercial ?
What are you using to play the VHS-C tapes ?
I also read in another post you made you have a GREX. That should be able to remove any copy protection on your VHS-C tapes . At least I think it should.