It has 6 small engines all together in the middle. Don't know that one.

EDIT: I mean lower RIGHT Can I change the title?

Its the Ass-End of a Gladiator

Oh, that was easy.. It looked more triangular.. didn't even think of that. Thanks Drasnighta.

If you're talking about the one deepest into the lower right corner, I concur with Drasnighta, that's the aft quarter of a Gladiator, from slightly above and the ship's portside.