If you intend to board from a latter station other than your boarding point, you ought to change that during/after the booking of the ticket. Else, the TTE has full right to offer your seats/berths to RAC/Waitlisted passengers.
In such cases, TTE should mark as "No show". You were supposed to file TDR within a specific time limit after the scheduled departure of the train. I believe, you have already missed the deadline.