Chart Not Prepared means the train's seat allocation is still in flux. Your status can change:
- WL → RAC → CNF (if cancellations occur)
- RAC → CNF (most common)
For distant journeys, the chart is prepared 3-4 hours before departure at the origin. Some trains prepare a second chart at major boarding points.
Keep checking your PNR status periodically. The closer to departure, the more accurate the prediction.