The original question is a bit ambiguous, because he could be asking what the redline is or he could be asking what max rpm gives the fastest time. I’ll assume he’s looking for a redline. It’s about 17,000, though you definitely don’t want to spend much time there.
At some tracks I hit 16,000 and a little bit more. If I’m bumping up near the redline that’s definitely an indication that I want to look at gearing down, as I’m likely not spending enough time in the fat part of the power band.