Champaran HumSafar Express : इन अजनबी सी राहों में, जो तू मेरा हमसफ़र हो जाये, बीत जाए पल भर में ये वक़्त, और हसीन सफ़र हो जाये. - Piyush Singh

I think it means that the TDR has been logged/forwarded to CR zone for review and action. And later on CR will update the status after confirming AC failure. Thats my guess but I can't find any definitive explanation.
.
Explanations for other status types are-
TDR STATUS:-
TDR...
more...

Entered : TDR has been filed successfully
Admin Approved : Refund Eligible case approved by IRCTC Corporate/IRCTC Zonal Office
Admin Regret : Non Eligible case rejected by IRCTC Corporate/IRCTC Zonal Office
CCM Approved : Refund processed by Concerned Zonal Railway
CCM Regret : Non Eligible case repudiated by Zonal Railway
GGM Approved : Refund Amount received from Zonal Railway and updated in IRCTC Database
GGM Regret : Non Eligible case repudiated by Zonal Railway and updated by IRCTC Zonal Office
TDR REFUND STATUS
Approved : Refund Amount received from IRCTC Zonal Office and updated for further communication to Bank
Sent For Refund : Refund Advice given to Bank
Refunded : Amount Refunded to the customer’s Account
.
You can send an email to tdrprocess@irctc.co.in to confirm what is the status of your TDR and whether you need to do anything.