Check this link for IES Photometric Viewer and IES Files:
http://www.eclipselightinginc.com/pages/download/photometric-ies-files.php
Which render extension (and version) do you use?
If you use V-ray, check this link for more info: https://docs.chaosgroup.com/display/VRAYSKETCHUP/V-Ray+IES+Light+|+LightIES