It looks like KB58547 was unpublished, probably because it's out of date. What manager version are you running? There should be other documentation specific to your manager version that should give you some answers.
We have NSM 220.127.116.11 and MS NAS on Windows 2008 R2 Ent.
This should be what you're looking for:
Near the bottom of page 124 is the "Configuration of RADIUS server in the Manager" section. That has all of the information I could find on using RADIUS with the manager, and it appears to match the information you would have found at KB58547.