The following profiles are in Lightroom 5.6 for RAW files (only):
The Sigma has profiles for Canon, Nikon, Sigma and Sony bodies:
The Tamron has profiles when used on Canon and Nikon bodies:
If you're not seeing them then either your LR version is too old or you're editing a JPG, as most profiles are for raw files only.
Here is Adobe's list of profiles and the version of LR and ACR they were added to:
Lens profile support | Lightroom 5, 4, 3 | Photoshop CS6, CS5 | Camera Raw 8, 7, 6