hibhilogin.js

// ==UserScript==
// @name         New Userscript
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://hib.iiit-bh.ac.in/Hibiscus/Login/?client=iiit&sub=OK
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    // Your code here...
    javascript:document.getElementsByName('uid')[0].value="username";
    document.getElementsByName('pwd')[0].value="password";
    var str=document.getElementById('txtCaptchaDiv').innerHTML;
    str=str.slice(0,-7);
    document.getElementsByName('txtInput')[0].value=eval(str);
    document.getElementsByName('sub')[0].click();
})();