According to the Guideline for Grant Applicants – 1st Call for Proposals, 17th of May 2017 is the deadline for request clarifications from the Joint Technical Secretariat and 24th of May 2017 is the last date on which clarifications are issued by the Joint Technical Secretariat.
Therefore, if you still have questions regarding the first call for proposals, sent them by tomorrow at the latest to JTS at:
Make sure you will get answers to all your questions!