Thank you for the reply. I call it atlas, but I think what I mean is parcellation/scouts (I used the following tutorial to obtain the USCBrain atlas: https://neuroimage.usc.edu/brainstorm/Tutorials/DefaultAnatomy?highlight=(uscbrain)) and it contains 130 something scouts. What is "missing" currently are the scouts.
If you right-click on the anatomy > Use template > USCBrain, the cortex that is added to the folder contains the SVReg scouts.
If you re-process the MRI with SimNIBS, it may delete the existing cortex surfaces (with the SVReg atlas), but it would replace them with other cortex surfaces with the CAT12 atlases.
And when I look in the anatomy tab, I can't select any scouts (everything is greyed out, see below):
You need to have a cortex surface loaded and displayed in order to have menus available in this tab.