TISS website is working now, you can check & can do your registration.

As tomorrow is last date so there might be a huge traffic on the website that's why it is possible that it could have got crashed.

So don't panic and wait for some time. Keep checking the status of website. Please try it through different  browsers and with a very good net speed so that there is no fault from your side for accessing the website.

You can try to access this website a little late night when traffic will be less and also if there is any fault in website then it could have been repaired. And if it still doesn't work till tomorrow then it can be a fault from other side. In that case generally application date gets extended.

So don't panic and keep checking website at regular intervals.