Dear Nelson Dylan,
on the Illustris webpage (http://www.illustris-project.org/data/docs/background/) it is announced that there will be Rockstar catalogs available in the future. Do you know when these catalogs will be released and will these catalogs also include subhalos?
Unfortunately this hope never came to fruition. We are thinking again about the possibility of running Rockstar for the upcoming TNG data release. But for now, there aren't any immediate plans to make this happen.