Convert TRA to TRC

It is unlikely .tra files from True Basic can be converted to .trc files which are compiled by the same program. You would need the original source code to work with them, or some kind of decompiler, no direct tra to trc conversion is most likely possible.

Simply put, it is impossible to convert TRA to TRC directly.
Thus, there is no so-called tra to trc converter or a free online .tra to .trc converter to be found.