There are always two possibilities in such cases:
1) Berth Multiplexing:- Confirmed Berths issued upto Manmad leaving the remaining leg vacant.
2) Individual Quota of "X" berths provided to Manmad or to a charting station prior to it where booking would be done on first-cum-first-serve basis.
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During...
more... booking only 3 Confirmed berths were available for the concerned journey leg or from Manmad to some station after Durg.
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After 3 Confirmed berths were also exhausted, the status moved to the General Waitlist prevailing in this train (Usually Start-End)
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For the Waitlisted Status, maximum booked was till WL 2 (Next passenger if booked would get WL 3)=> Thus status was showing WL 3.
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However, due to cancellation the status had came down to RAC 17=> (Next passenger if booked would get RAC 18)=> Thus status was showing RAC 18.
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Thus, the Waitlisted Passengers got their current (Booking) Status starting from RAC 18.
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Since maximum RAC Limit defined for GN Quota against this train is RAC 18, the status again moved back to Waitlist (WL 1, WL 2).
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The Current (Refreshed) Status you see is due to cancellations which has taken place after this ticket was booked)