I am replacing a toilet in my parent's house (putting the same one
back in). I removed the toilet because it was leaking through to the
ceiling below. I had to pull out and replace six tiles, and I will be
going back tomorrow to reseat the toilet, having given the mortar a
few days to set.

When I took the toilet out, the plastic insert that comes with the wax
ring was crooked, and I assumed that was the reason for the leakage.
While I had the tile out, my father put a torpedo level on the top of
the drain and determined that it was not level. I don't know how bad
it is, because I hadn't really noticed. Based on the fact that I
hadn't noticed, I am assuming it is not too bad, though. The drain is
even with the subfloot, so there is the tile and mortar width between
the bottom of the toilet and the drain.

There's the background, here's the question: I was planning on simply
reseating the toilet with a new wax ring. Do I have to do anything to
account for a slightly off-level drain?