The NJO Republic, because of their technology over the Sith Empire, Seperatist, and OT Empire. I'm not really educated on the Infinity Empire(could someone send me info in a private message), Though Revan would put up a good fight with his military tactics, which would allow him to probably beat the Seperatist, but not sure about the OT Empire. They have the Death Star. The New Republic...spawned from the Rebel Alliance has seen action over 40 years(correct me if wrong) and their adrenaline is still pumping, so in turn the New Republic would win... 💃
25 years, the rebel alliance had been fighting for at the most 25 years by ROTJ probably less...
And the republic Alliance ran mostly, sneak attacks hitting them were it hurts but where they are not facing real fleets. They always avoided fighting like that becuase they would lose. Their numbers were to small their ships less powerful... The Empire was a lot more powerful then the rebel alliance