The codec of the output video
That part isn't relevant. He was asking about the codecs of the videos used in the project, not what you exported out of it.
But perhaps even more important might be the preview codec you had set for the sequence when on the Mac. If it was ProRes, you might be hosed and have to complete the project on a Mac. If it wasn't ProRes, then give this a try.
FAQ: Why are some codecs and sequence presets missing from my installation of Premiere Pro?