Based on the shape I would of thought difficult to pull out (dentless repair) although thin being a chassis rail it will be a heavier gauge than a normal panel, a bodyshop could do a welded repair easy enough but obviously more expensive.
That drain hole makes a handy place to put a tool in to try to pull the bottom face flat, and that might bring most of the bowing on the vertical face. But probably a body shop, though the kind of thing that wouldn't take long to do if you get the right person.
