sir, the 120 mdays norm has already began today ie.10th march. but 90 days or 120 days the no of people booking in irctc will not jump drastically. in fact normally all AC tkts in mumbai-chennai trains is sold out on the frist day itself, but today i was able to book AC tkts both in 2 tier and 3 tier for july. so many people are not aware that 120 days norms have started