WAP-7 - तेरे जैसा यार कहाँ , कहाँ ऐसा याराना , याद करेगी दुनियां तेरा मेरा अफसाना. - Arjun Rai

What exactly is PNR Prediction ?
And when someone predicts as Confirm OR RAC OR WL, does he/she do any kind of study based on PNR numbers / DOJ / Train No. etc or is it PURE PREDICTION.
Meaning just a GUESS Work? Or is there any SYSTEMATIC way of predicting.
Please put some light on this aspect.
Thanks.

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