$re = '/<div class="col-xs-6 col-sm-4 col-md-4 col-lg-4">(.*?)<\/div>/si';
$str = '<div class="col-xs-6 col-sm-4 col-md-4 col-lg-4">(NÚMERO ILIMITADO DE CARACTERES)</div>';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php