The original version of DPS is not in InDesign CC 2015. It is replaced with DPS 2015
Read about it here:
For questions pertaining to the Digital Publishing Suite tools please visit the Digital Publishing Suite forum: http://forums.adobe.com/community/dps
For questions pertaining to the Digital Publishing Solution (DPS2015) tools please visit the Digital Publishing Solution forum: https://forums.adobe.com/community/digitalpublishingsolution
If you use CC 2015 it is no longer there, CC 2014 is the last version that supports Folio's.