If you are printing at 300DPI (a good resolution), it should yield you a good 6R print size. If you are willing to sacrifice a little at settle for 200DPI, it should give you a good super 8R print.
However, there will be some cropping as "1944 by 2592" does not fit into the 2 x 3 (or 3 x 2) ratio. You either have to do the cropping yourself (using one of those image editors) or leave it to the lab.