There are 3 types of calls:

1) Part Call: You can apply for part call if you are 3 months into PTC and you have passed your Part B exams on the 1st attempt. But usually, applications are seldom because it means you will get arrowed by many partners to attend court on their behalf.

2) Monthly Call: These are the monthly call dates that are shown on the Supreme Court's website. Note that there are no monthly calls in June & December. Note that you have to get your own mover and some movers will charge a fee.

3) Mass Call: Once a year and the call with the most admissions. Most trainees will wait till Mass Call as the hassle is much lesser since a common mover has been arranged per batch. Also, most want to "graduate" together with their university batch mates.