PRS is the ticket counter in railway stations where book the tickets. And I can't tell you the special techniques as they are against the law, even i don't know much more about those techniques, you cant apply those tricks as you don't know them. If you have some emergency and if you want to book through PRS counter in railway station then I have some tips and tricks for you:
1. Try those station counter which are very less popular or congested.
2. If you can't find any less popular booking...
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counter then just arrange a guy who can sit in the Que for whole night and just write your name on behalf of him, you will find those guys around the station. They will take 100-200 rupees to do this job.
3. Or if you don't want to pay anything and can wait in the "Q" by yourself then go ahead and wait, try to be first in the "Q".
4. If you find above tricks are not working then just request ticket booking officer in the counter and tell your emergency needs, may be possible they will help you.
If you want to book an e-ticket on IRCTC by yourself then here is a trick. But try to book it if you have good internet connection speed.
Install this extension on google chrome. click here
After installing you will find a new icon on the address bar, fill all you details and click "save and book later".
And at the time when tatkal opens just click on "Book now".
Now all will be done by a script you just need to type the CAPTCHA.
Hope this helps.