The answer really depends on what you are expecting:
- If you are looking for some behavior not in a terminal emulator, Emacs could detect the control modifier independently of the actual character.
- In a terminal emulator, the usual effect of the control modifier is to logically-AND the value of the character with 0x1f (31). The ` character's value is 0x60 (96), so the usual result would be 0 (ASCII NUL). You can do this in Terminal.app with a control modifying the space character.
Just to complicate things a little, xterm can be told to send an escape sequence such as
ESC [ 2 7 ; 5 ; 9 6 ~
for control `, however that's not implemented by other terminal emulators. (This is the modifyOtherKeys feature mentioned in the manual).