Browse button greyed out though last date given as 27.01.2019 on the Candidate Dashboard
you can try these steps may be they are helpful to you
try different browser
delete the cookies
visit the page again and select the file that you want to upload after before clicking on submit or upload just press reload button and click submit or upload button before the reload of page it may help you.
as you dont have lots of time you may visit cyber cafe.