I am using Lightroom CC, release 2015.3, and RAW 9.3, on a Windows 64 bit machine, and when I am in the Develop Module, and Lens Corrections Panel, my camera/lenses are not listed. I am using a Pentax K5 and mostly stock lenses, all current. This page on the Lightroom website lists many Pentax lenses, including the stock lenses, so they should be available in LR. Lens Profile Support List Camera Raw Lightroom
But in fact no Pentax lenses are shown at all in the Develop Module/Lens Correction panel, none; Pentax isn't even listed as a maker. But then there are some I've never even heard of, like Parrot. What gives, why wouldn't the Pentax lenses be showing?
Lens profiles are for raw files, mostly.
If you don’t see your lens that you normally see or not even your camera manufacturer, your current image is likely a JPG or TIF or PSD, some format the isn’t raw.