$.extend($.fn.validatebox.defaults.rules, {

        requireRadio: {

            validator: function(value, param){

                var input = $(param[0]);

                input.off('.requireRadio').on('click.requireRadio',function(){

                    $(this).focus();

                });

                return $(param[0] + ':checked').val() != undefined;

            },

            message: 'Please choose option for {1}.'

        }

    });

<input class="easyui-validatebox" type="radio" name="yes_no" value="1" data-options="validType:'requireRadio[\'#ff input[name=yes_no]\', \'Yes or no\']'">Yes

<input class="easyui-validatebox" type="radio" name="yes_no" value="0">No