It only checks for torrents of the same imdb, not the specific request. Preview: http://i.imgur.com/HCmqiH3.png

script.user.js

// ==UserScript==
// @name           Check KG for PTP Requests
// @namespace      https://savagecore.eu
// @description    Add link to PTP requests page if found at KG
//
// @version     0.1.0
// @include     http*://*passthepopcorn.me/requests.php*
//
// @connect      karagarga.in
// @downloadURL  https://gist.github.com/SavageCore/2432769391b727b022f7c509b1429757/raw/f757e33f464d22d31e565b5c9514ab4fc468bb92/script.user.js
// @grant        GM_xmlhttpRequest
//
// ==/UserScript==
if (window.top != window.self) // Don't run on frames or iframes
{
    return;
}

var imdbIDs = Array();

[].forEach.call(document.querySelectorAll('#request_table > tbody  > tr'), function (tr) {
    var element = tr.querySelectorAll('td > .imdbtitle > a')[0];
    if (element) {
        var regex = /http:\/\/(?:www\.)?imdb\.com\/title\/(tt[^/]+)(?:\/)?/gm;
        match = regex.exec(String(element.href));
        if (match) {
            imdbID = match[1];
            imdbIDs.push(imdbID);
        }
    }
});

// Foreach request page do search
for (var i = 0; i < imdbIDs.length; i++) {
    // Search KG
    GM_xmlhttpRequest({
        method: 'GET',
        url: 'https://karagarga.in/browse.php??search_type=imdb&search=' + imdbIDs[i],
        onload: function (response) {
            var regex = /<h2>No torrents found/;
            match = regex.exec(response.responseText);
            if (!match) {
                // Torrents found append link
                var regex2 = /http:\/\/(?:www\.)?imdb\.com\/title\/(tt\d+)/;
                var match2 = regex2.exec(response.responseText);
                if (match2) {
                    imdbID = match2[1];
                    element = document.querySelectorAll('a[href*="' + imdbID + '"]');
                    tags = element[0].parentNode.parentNode.querySelectorAll('.tags')[0];
                    tags.innerHTML = tags.innerHTML + ' | <a href="https://karagarga.in/browse.php?search=' + imdbID + '&search_type=imdb" target="_blank" style="color: #43A047">KG</a>';
                }
            }
        }
    });
}