the answer to all your questions and doubts is:
there is no K12
the latest version of tantra online released by HANBITSOFT is K6 which has the new map called "Dragons Cave" or "Dragons Map" (i forgot the actual name)
but if you have played in PH before it was wiped out, you should probably be aware of it....
anyone can make their own server, make new weapons, armors, and accessories....
but no one can ADD another map except HANBITSOFT