I have a Sigma 150-600mm f/5-6.3 lens and it does not show up as an option in the "model" drop down list. Why is this?
There are not profiles for every lens that is available. That could be the problem. Another thing to consider is that most lens profiles are for raw images only, not JPEG. If neither of those reasons apply then you can get the Adobe profile downloader Which gives you access to profiles created by other users. If you don't find a profile available there then you can download the lens profile creator and create your own profile. You can find the profile downloader and the lens profile creator by searching on the Adobe website.