Probably 6:5X. Hard to say with resurfacing. Porsche supposedly expected 7:05 and went way faster than that, so not sure if the surface is just vastly improved this year or if they went in with moderate expectations. GT would be a lot faster through a couple of the real long sections but the Cup 2 R tire is better. RS also makes a lot more downforce with the mammoth fixed wing.
I once asked if they'd used their sophisticated sim equipment to do the Ring, and was told it was a sub-7. They are pretty accurate with that stuff. Should let Müller do it in real life. Has plenty of experience racing there.