$re = '/\bR-?(?<Lower>\d{9})\b/m';
$str = 'ABCD/SESSION REMARKS/SESSION REMARKS_002FT2213700215_ /CODTYPTR/049 //R101841246/058 Session 220517080 REF: 02024741031486605002FT221
"R-101880298/GTB - GTB 981018802981 from GENERAL To GENERAL REF: 0000202582697981018802981 REF:205000000000760015362205171040" and "R101880298/GTB - GTB 981018802981 from GENERAL To GENERAL REF: 0000202582697981018802981 REF:205000000000760015362205171040';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($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