Can anyone please tell me what the reading should be on the Moisture Meter when testing?

I was told by the company that is going to install, if we hire them, that our level reads 6 and they said that was good and we could install hardwood or engineered wood.

Thanks

RCL

Tell us what a good hygrometer tells you, what the interior ambient conditions are, and I can tell you where the MC of the wood and subfloor should be.