[loneWolf]

Получилось, мож кому пригодится

window.addEventListener('load', function() {
    xhttp = new XMLHttpRequest();
    xhttp.open('GET', 'tt_inworld.json', true);
    xhttp.send();
    xhttp.onreadystatechange = function() {
        if (xhttp.readyState == 4) {
            var listFlags = JSON.parse(xhttp.responseText);
            newULFlags(listFlags);
        }
    }
    
    var newULFlags = function(data) {
		var divFlags = document.getElementById('flags');
       
		var list = [];
	
		var cols = 3;
        var count = Math.ceil(data.length/cols);
        var cnt = 0;
		var str = '';
		var items = [];

			data.forEach(function(element, key) {
				
				str = '<li style="background:url(http://test.ru/images/flags/' + element.flag + ') no-repeat;" id="' + key + '">';
				
			   if (element.SiteInWorld.length > 1) {
				str += '<span>' + element.world_name + '</span>' + '<a class="name-title" href="' + element.SiteInWorld[0].link + '">' + element.SiteInWorld[0].title + '</a>' + '<a href="' + element.SiteInWorld[1].link + '">' + element.SiteInWorld[1].title + '</a>';
				}
				else {
					str +=  '<a href="' + element.SiteInWorld[0].link + '">' + element.world_name + '</a>';
				}
				str += '</li>';
				
				list.push(str);
				
				cnt++;
                    if (cnt == count) {
					var str1 = '';
                        str1 += list.join('');
						items.push(str1);
                        cnt = 0;
                        list = [];
                        var mod = data.length%3;
                        if (mod === 1) {
                            count = Math.ceil(data.length/cols)-1;
                        }
					 }
					
			});
			
			items.forEach( function(el){
				var ul = document.createElement('ul');
				console.log(el);
				ul.innerHTML = el;
				divFlags.appendChild(ul);
				
			});
	};
});