Rare drop at 60s, regardless if the 60 is reached by scroll or free draw. usually, of course, this happens after you spent 40 or 50 scrolls in 10x, and then eventually reached ur 60 with free draw here and there.

SN is a rare. Now, I'm not entirely sure if I got him off free draw, but I did get him as a ftp, i also got jigokudo in the same day off free draw(each treasure being counted separately) to confirm the fact that rares do in fact drop from free draw, when conditions are met.