I was trying to deploy Havana version with IPv6, but it seems not working at all. I have gone through the articles from Nephos6, it also state that IPv6 in Havana is not working with its original source codes and installation. Instead it has to do plenty of modification.

is the answer that IPv6 not supported in Havana version???

IPv6 NOT Ready in OpenStack Havana: http://www.nephos6.com/blog/?p=160

Whitepaper: http://www.nephos6.com/pdf/OpenStack-Havana-on-IPv6.pdf