Yes, I think you can fix that one, can't tell for sure from the picture. I've fixed a couple of rims that looked worse than that one. I use blocks of wood on my garage floor and press against the concave side of the rim (all spokes removed). I had to stand on one rim. I've heard of mechanics on road tours slamming wheels against oak trees to straighten tacoed wheels.
After you get it back together your tension meter will tell you if it's straight enough. All of the spokes should have tension within 10% of each other, I would shoot for 5%.
Al