Possible Unified Galactic Systems, ala Mass Effect, Nova Core, Green Lanterns. 

Or Frontier Justice with mismashed ships and gear

From what I’m thinking Let’s drop any possible connections to Green Lanterns. No power rings, or Emotional Spectrums for Space Police Corps or any off shots thereof. Maybe keep it mostly technological. Bio Soldiers, Cyborgs, Robots. Giant Xenotype Aliens maybe? All of the above?

Hellis suggested 
Galactic Confederation of free Planets
Free Planets Marshals.