training wheels
I assume you may be from either ETOPS or Magellan?
The Asian Aviation Training Centre (AATC) Bangkok will EASA, Thai DCA (and other NRAs) qualify an ATR 72-600 FFS and an ATR72-600 eFTP this coming week, so that will go a long way to reduce any backlog.
Whilst AATC have absolutely no operational or financial association with ATR Toulouse, 72-600 Type ratings and recurrency will be performed there as well as Dry Lease.
As an aside. With the (EASA) regulatory impossibility of having a differences course from -600 to -500 (or even non PEC versions) I am somewhat surprised that more crews are not opting for a -500 TR with a -600 difference course to avail themselves of far greater career opportunities!