So lets assume we have ORS on table and Rebel in hand as our last card - will ORS give resources in time to spend them on card played from rebel?

I'd say no. You have to resolve an effect fully before resolving the next effect, and ORS triggers after playing the last card in your hand.

I agree with Abyss, you won't get the resource in time to pay for the card you're getting back.

Play Rebel, it enters limbo to finish resolving.

ORS triggers and the ability enters the queue.

Finish resolving Rebel.

Resolve ORS trigger to gain a resource.

That makes sense to me. I wouldn't be surprised if FFG ruled the other way though, saying the triggers are simultaneous and thus you get to choose (since both trigger from you playing the card Rebel)