If it’s really missing frames, you might be able to use Twixtor for that. You’d be on your own, since I’ve never used it to replace missing frames due to an error — only to create regular intermediate frames when slowing down footage.
You could also try importing into AE and removing pulldown. However, I’m concerned that some moron down the line messed up the footage. You should get the exact history of the footage, what it was shot on (film? video?) and what was done to it at each step. Try to talk to the people in the process, and try to get the original footage out of the camera, or the edited master at least. If too much was done to the footage, you may be in trouble.
You should also search the COW for “judder”. On finished footage (not an AE project in progress), it can’t be fixed, only ignored.