BOSTON/Hyde Park - A group of over 30 housing advocates - many of them tenants in apartments subsided by the U.S. Department of Housing and Urban Development - held a rally in Cleary Square Saturday in support of a raft of proposed legislation and treaties at all levels of government that would help low-income families remain in their current apartments at lower than market rates. The event was organized by the Mass. Alliance of HUD Tenants, a statewide coalition representing tenants in privately-owned, HUD subsidized apartments.