$re = '/[\s](rs|price)?([\s.]*\d+[\s\d.]*)(pkg|k|(?:la(?:c|kh|k)|crore|cr)s?|l)[\s.] /m';
$str = '65 lac this is 55 lac. and more price 100 lac. randome text to test price45 crs. and 65 cr and to test its matching rs 3244 k like rs 55k. to its matchibg 65 cr. but not 65 cr als not matching price 123 lac more of it 55 crs.
';
preg_match_all($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