^I believe the model actually had only five limbs. It's sometimes called the "Quintopus." Although the creature in-story was presumably supposed to have eight limbs; we just never saw them all at once.
That's the anecdote I read a few time over the years myself, 5 limbs. But in that 90 minute retrospective Ray himself claimed it had 6 limbs and then the presentation cut to another filmmaker (I forget whom) who also stated 6.
So, I don't know what to believe any more. I'm beginning to suspect I keep "slipping" into divergent quantum realities because people will state one thing and then later claim they never did.