Deadline for VCDX5-DCV initial submission is already passed as of June or July of this year (2017)

If you've already submitted a v5 design and defended, you can still re-defend for the foreseeable future (per Karl Childs, no expiry date for second/third defense on v5 as of yet)

If you haven't submitted your design yet, you can only submit for VCDX6-DCV now.

HTH!