The deadline for applications to the IPC was December 1, 2017. This was for enrollment in April or October 2018. There will probably be another call in June/July 2018, for enrollment in October 2018.
In any case, keep in mind that the first thing applicants must do is selecting the research group(s) they want to work in and contact the professor(s) of the group(s) in order to obtain a "Letter of Conditional Acceptance". The first contact should happen as soon as possible and at the latest four weeks before the application deadline. The list of groups is found here
Please contact us if you have any question or need help in contacting the professors.