I want to use FLIRT to apply registration on T1w images.
But I am quite confused if FLIRT automatically transforms images to standard MNI152.
This is the command that I am familiar with. It should align all images with the reference image.
What about the MNI152?
flirt does not automatically align to MNI. You need your reference image to be an MNI template T1 brain, e.g., $FSLDIR/data/standard/MNI152_T1_1mm.nii.gz.
MNI is a brain template that is distributed with some softwares, including FSL (see the path relative to $FSLDIR in my last reply). You can align your input image to MNI space with commands such as flirt.