This is a rather informal listing of types of railcar vehicles I've come across.
Lightweight Diesel Railcar (RBE)
Original size.
Railcar RBE.2546 arriving at Puzundaung Station, en route for Yangon. The railcar is provided with 'Automatic' couplers, presumably for attaching a trailer car.
Diesel Railcar, 5000-series (RBE)
Original size.
Puzundaung Station: On the right diesel railcar RBE 5011, believed to be of Japanese manufacture, arriving from Yangon. Elsewhere, a defunct unit similar to RBE2011 was seen, locomotive hauled, in use as a coach. A second unit, RBE 2522 (similar to RBE 2508 illustrated below) can be seen on the rear of RBE 5011.
Diesel Railcar, 2500-series (RBE)
Original size.
Diesel railcar RBE 2508 under repair at Katha.
Railcar Trailer Car (RBT)
Original size.
Diesel railcar trailer car 827, paired with the repaired RBE 2508.
Railcar Trailer Car (RBT)
Original size.
Diesel railcar trailer car 802, forming part of a locomotive-hauled train.
Very-Lightweight Diesel Railcar
Original size.
Very-lightweight diesel railcar (chopper couplings, livery white with yellow roof and red line) leaving Myo Haung with three 4-wheel coaches LZBT.
Recent Developments
These DMU spotted adjacent to Yangon Central station in February 2013 may be part of the Japan International Co-operation Agency (JICA) project in Myanmar. The JICA website referring to work in Myanmar says "a proposed multi-million dollar project will upgrade the maintenance and safety of railroad infrastructure, most of it dating from the pre-World War 11 British colonial era". The above picture shows what may be new or rebuilt Japanese units. The unit on the left carries a Myanmar Railways style running number 'RBE 2586' whilst the unit of a different on the right carries the number '301'.