I don't think a tiller would be good, it will leave it too rough and clumpy and will destroy any grass that might be there. Lightly discing it may be better, if necessary. It all depends on how rough it is. If it's really rough, a power rake (Harley Rake, etc.) may be worthwhile.
Years ago we bought a lot that had 5 acres of really, really rough and rutted ground. I did a lot of smoothing with a disc and a box blade, and then final smoothing by dragging a section of chain link fence weighed down with some sections of telephone pole. That worked well but I got a lot of seat time in the process....and stirred up a lot of dust.
Ken