I've always thought the Kong could put up a good long fight against the Indomimus than the much dumber Vastatosaurus Rex. (a dinosaur that is waaaay bigger than the T-Rex) The Indominus on the other hand has longer arms with a claw that is strong enough to pierce a .50 cal proof glass and a skin that also a .50 cal couldn't penetrate so they should be able to seriously hurt Kong here but then again, Kong's size, strength, and extreme maneuverability is what give him a great advantage.