My friend's character bugs when he enters play tests

This is what it looks like from my friend (theres a tool in starter pack btw so that doesnt work too)

This is what it’s supposed to look normally

It’s only when he’s in r6

The tool probably doesn’t support R6 and instead only supports R15. I would completely disable R6 from the game that way the game doesn’t do that again.

how can i change it so that the tool supports r6

Well you would have to edit the code to where R6 is supported.