IAP / "Instrument Approach Procedure (IAP) Charts" What does "Procedure NA" Mean?
Although the wording on the chart is very confusing, it appears to indicate that you can not make a course reversal at the VORs themselves. Probably due to the congestion of the airspace and associated airways. This is only the case when using the VORs for navigation to the IAFs since neither of the VORs is an IAF. However, the IAP is an RNAV IAP. So, you can disregard the VORs and use GPS only to navigate to the IAFs as long as you stay above he 4200 foot Minimum Sector Altitude and cross the IAFs at or above 4400 feet. Beware of the higher terrain with MAximum Elevation Figures of 5600 and 6600 feet NNE of the IAP.

In other words, it means that the entire procedure is invalid if you are using VORs to navigate to the area in some circumstances. If you are coming from the North and West, you are required to use LEB. If you are coming from the South and East, you are required to use CON. If you are using GPS only, you are required to navigate to the IAFs directly (not necessarily Direct-to) using GPS and not VORs.