I am sad to say, that all of the KDF RP fleets died shortly after launch and prior to the Klingon mass exodus.
Most of the Klingon player base are PvE, PvP, and STF based. There are some fleets that are established in both factions, but the KDF portion is lacking in RP.
So, the best option is gather 4 players to meet at the warrior's hall and create your own fleet (I'll be in it). But make sure if you decide to do this that you have a good foundation of how you and the group want the fleet to be like.