Try TYPE with a file containing Unicode (UTF-8) characters. OPTION //Unicode=Yes has no influence on the (incorrect) output. However: CHCP 65001 will do what you want.
BUT: Try this (with CHCP 65001 set) on the TCC command line: REN test töst
So, here the input is the problem. In conclusion: No working Unicode support in TCC (I haven't tested this with TCmd as I don't use it...).