In real-life TACAN beacons require a TACAN receiver to receive the course (OBS) information of the beacon. With a civil VOR/DME receiver you only receive the distance (DME) to the beacon.
The problem in MSFS is that there are no dedicated TACAN gauges, so it's not  possible to perform TACAN approaches, because this requires course information of the beacon.
To overcome this problem i've modified the TACAN beacons in Germany so you can fully use them with civil receivers. And so are able to fly TACAN  approaches.
 
NAVAIDS:
116.40    EGB EGGEBEK
113.50    WTM WITTMUNDHAFEN
117.10    NDO NORDHOLZ
111.80    SWG SCHLESWIG
109.50    KHD KIEL
115.30    HNT HOHN
108.25    LAG LAAGE
108.05    NEG NEUBRANDENBURG
108.35    OSB OSNABRUCK
109.00    HOP HOPSTEN
117.25    HOZ HOLZDORF
117.20    MEM MEMMINGEN
108.80    LAB LANDSBERG
111.40    IGL INGOLSTADT
113.60    ERD ERDING
108.10    GIX GEILENKRICHEN
109.50    SPA SPANGDAHLEM
117.10    BUE BUCHEL
116.95    HND HAHN
114.10    WIB WIESBADEN
113.40    RMS RAMSTEIN
109.00    HDM COLEMAN
111.00    GBL GIEBELSTADT

CHARTS:
Charts of the TACAN approach can be found and downloaded at (look under procedures):
http://www.cenor.org/