The reel seat is basically just a sleeve over the butt section, not many rods have a section join under it.
On many rods there is a duplon section above the reel seat, just in front of the reel, as basically the rod manufacturers want you to feel good holding on the rod.
If there is nothing below the reel seat, towards the butt, it should be possible to slide it down and reglue it, but use a decent two part glue.
However, cheaper or foreign manufactured rods can be a problem, because the reel seat may well be over a sleeve, and the sleeve over the rod blank.