As a helicopter test pilot, you should be able to answer your own question, as you should be able to read and interpret the manuals..
Your questions refers to the ABILITY to land there.....there is a clear answer to that:
It depends.
Helicopter landing weight, Field elevation, Pressure Altitude, Wind, Dimensions, Power Available....
The categories describe exactly that-the CATEGORY a helicopter is operating in.
It describes the margins, the equipment and other things NECESSARY to operate in that CATEGORY...