Can I adopt if I'm moving to Canada in 6 months?

You can move to Canada (or anywhere else in the world) once your adoption is finalized. I doubt six months is enough time to get a placement and then finalize as the post-placement period before finalization is usually six months.

After placement, but before finalization, you can travel to other states, and countries with the permission of the agency who is supervising your post-placement, but you cannot move to another state or country until after the adoption finalizes.

Please note, that in order to travel to another country before the adoption finalizes you will need a court order to get a passport for the child. This is not a difficult process, but you need to be sure to plan well in advance so that you can get the court order before you apply for the passport.