For starters, enlighten us on your current configuration that you attempted to configure netflow on the 6800x.
What IOS are you running?
What kind of Catalyst 6800? Show Ver would help along with what you are trying to accomplish? Have you looked at the documentation as this is the normal starting point to look for answers prior to posting on the forums.
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/fnetflow/configuration/15-sy/fnf-15-sy-book.html
