As the vast majority of the places will be gone by the time the interstater gets allocated to them in category 2, I would simply preference them in the order that you would like. As a general rule, your chances at a very popular hospital (i.e. like "the big 4") is pretty close to zero, owing to the fact that all of the places to these networks are allocated in the first round offers - so generally the only way that a category 2 would be allocated a place there would be if a Category 1 was offered a place there and declined it to go interstate. As interstate rounds would happen later, in general, then oddly enough, from personal observation, I have noticed that people in Category 2 have a better chance at a very popular hospital network if they actually get allocated in later offer rounds - this gives the Category 1 applicants time to receive offers from other states and thus decline their offer in NSW. That said, as a Category 2, you have no control over which Category 2 offer round you receive an internship in (HETI will allocate a random selection of Category 2 applicants each round by this system).