this thread may be a repeat but i just want to make this once again to say once and for all that the thailand clan of 3-k Batteries is the best by sheer number. :rofl
In clan, do you mean blood related? The 3-K battery is a company name adopted by thai boxers due to their sponsorship. Do do not even come from single boxing gym. If it is a boxing gym, then the Freddie Roach gym would probably have the most champions today and if you mean boxing families,then probably the Spinks who had 3 champions (I do not really know other families with that amount of champions).
Clan? Let me think for a second. The Mayweather's come to mind. Or Andrew Golota's fans in Chicago, they may not be related, but they are willing to flip cars to get what they want.