$result = $link->query("SELECT * FROM News ORDER by ID DESC LIMIT 6");
SELECT * FROM News ORDER by ID DESC LIMIT 6 OFFSET 6;
-- сокращенная запись
SELECT * FROM News ORDER by ID DESC LIMIT 6, 6;
$limit = 10;
$page = 3;
$offset = $limit * ($page-1);
$sql = "SELECT * FROM News ORDER by ID DESC LIMIT $offset, $limit"; // внимание, при использовании запятой сперва оффсет, потом лимит!