IPV6 and settings for a ubiquiti - amplifi dual-band mesh wi-fi system

I replaced my router today with an ubiquiti - amplifi dual-band mesh wi-fi system (HD Model with remote antennas).  I am working on fine tuning the configuration.  One item is the IPV6 settings.  Xfinity appears to allow IPV6 so I selected it.  Then it asks for the Network type and the two choices are DHCP6 and 6to4.  I have researched and cannot find specifics.  At this point it is set for Network Type of DHCP6.  Is that the correct setting?  I do like to know how things work so please elaborate.  My setup is an SB8200 customer owned modem and this router which routes Network hard cables to three Linksys switches which go to various devices.  WiFi of course is used also for mobile devices and the ubiquiti - amplifi dual-band mesh wi-fi system has two MESH antennas that plug into electrical outlets to extend the WiFi signal.  

Thanks