Chrono Trigger in FF6?

Chrono Trigger and andd FFVI have a similar SPC core although CT's SCP core is a bit more advanced than FFVI. The hex values for the rests, octave changes and notes are the same. The are some commands that are different though but I never imported a song from Chrono Trigger. The offsets of the songs in CT can be found in this thread.

So you could find the offset of your song in the CT ROM and copy the data in FFVI using any hex editor that has a copy/paste feature (not WindHex).
Then you have to adjust the 18 channel pointers and change the commands that are different from the two SPC core.

The next step is changing the instruments. There is an utility to switch instruments (found here), but that doesn't change the BRR samples if you need/want to. The rest of the job is tweaking the song so it sound really close to the original.

There is no magic trick to import a song and you will learn with experience and will have to try different things to tweak the song as an example. You can refer to the music composition tutorial for more details on the commands. Good Luck!

Edit: Well Nattak was a bit faster than me on this one lol