$re = '/(?<=\(INR\))(.|\n)*(?=Due Date)/m';
$str = 'Format : ExpoHub
123456789
expohub street
ABC
123456
India
Billed To Date of Issue Invoice Number Amount Due (INR)
Nagesh Reddy. 22/04/2020 873101. Rs.26,178.00
Due Date
22/05/2020
Description Rate Qty Line Total
Shared Hosting Rs.25,878.00 1 Rs.25,878.00
LateFee Rs.300.00 1 Rs.300.00
Rs.0.00 1 Rs.0.00
Subtotal 26,178.00
Tax 0.00
Total
Amount Paid
26,178.00
0.00
Amount Due (INR) Rs.26,178.00';
preg_match_all($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