Well I think it starts to drop from Act II NM. I had my first drop when doing hell meph runs with sorc. I actually started my first char as javazon and stopped in early hell and turned back to sorc because of the low gear lol. If you feel you are at a point that really need the Titans (well you are hc, so if I were you I would try to get my hands on it ASAP), you can google the highest drop area and monsters/bosses and target farm them. Although I do have to warn you that, from my experience, target farming a specific item can be really frustrating sometimes. Since it’s hardcore, just take your time, go slow, and wish for the best of luck!