Saw no pics.
I would not rush to anchor a gate off the garage framing.
Pics appeared when I looked at this again. Of course you can hang a gate from an anchored post.You will want a 2 by to a stud in the garage for the hardware latch and support. Depending on the gate type you finally choose? Give it cross support or turnbuckle it so you can adjust it back to square as time goes on. Putting an adjustable wheel under the garage end will take stress off the post it is hanging from too.
I would not rush to anchor a gate off the garage framing.
Pics appeared when I looked at this again. Of course you can hang a gate from an anchored post.You will want a 2 by to a stud in the garage for the hardware latch and support. Depending on the gate type you finally choose? Give it cross support or turnbuckle it so you can adjust it back to square as time goes on. Putting an adjustable wheel under the garage end will take stress off the post it is hanging from too.