The Taiwanese Government has announced that the US will be supplying Mark 48 heavyweight torpedos for Taiwan's two relatively modern subs. The Mark 48s (see diagram and Youtube below) are for Taiwan's two 1980s Dutch built Hai Lung (aka Chien Lung) class submarines. The current torpedos on the Hai Lungs are listed (right sidebar) as being German made AEG SUT (264s?).
The two Hai Lung's will be undergoing life extension programs over the next few years. The life extensons are presumably at different times to allow at least one Hai Lung to be operational. They are also likely to receive modern, but basic, US combat systems (see Diplomat pay-site).
Taiwan's other two submarines (1940s-50s era US built) named Hai Shih and Hai Bao - are simply too old for weapons modernisation and are probably not operational.