itt training

u have to complete itt before starting articleship

Now it has been announced by the institute the completing ITTP is not a criteria for appearing in exam. But you have complete it before you join articles that is after you cleared the first group.  ICAI's Announcement is available in the following link. https://220.227.161.86/20130announ060810a.pdf

Anytime before joining Articleship !

Go through the announcement given in above post.