Some of the suites ($$$$$$) can accomodate that many, however, your most economical alternative might be to book adjoining cabins. Good travel agents are made for situations like this.
Explorer of the Seas October 2013
Caribbean Princess July 2006, May 2010 & November 2012
Monarch of the Seas November 2008
Crown Princess November 2007
Celebrity Zenith November 2005
Enchantment of the Seas August 2004