Not necessarily. All that the list does is show you which unit issued the code. The a/c may have kept that code after transfer to another unit (or not),& will most likely be speaking to another unit when you see it on FR24. If so, this gives no indication of which frequency is being used.
The only useful clue you are going to get from FR24 is the a/c's geographical position. If you know this & you have knowledge of which ATC unit would be controlling it, from the a/c's position; & you know which ATC sector will be controlling it, THEN you may be able to determine the radio frequency in use.
In any case, even if the a/c is still working the originating unit (which issued the code), the SSR code does not tell you which R/T frequency it is using.