It saves in the same place as .minecraft
Navigate Through C:\Users\ (Your accounts name) \ Appdata \ Roaming \ .techniclauncher \ Tekkit
And It is the same as a .minecraft folder but with mods, If Appdata isnt there you must enable viewing of hidden folders.
You can also Search by doing this :
If its a windows, Press Function (key in between ctrl and alt) and press R, Then type in %appdata% and press Run
If Function + R doesnt work Go Into Start menu and Press run
For Mac And Linux etc, Find How To navigate to .minecraft, but instead go to .techniclauncher