Tnank you Covarr.
I tried x360ce 32bit (cause FF6 is 32bit game) to set the gamepad to work;
x360ce 32bit source is from;
https://github.com/x360ce/x360ce
The game FF6 seemed to require xinput1_4.dll instead of xinput1_3.dll which is installed normally in x360ce. So I changed the dll name to xinput1_4.dll and selected "32bit ver1.4", re-launched x360ce and clicked "start FF6" from x360ce.
But had no luck, when I pushed X button the game made abnormal termination going back to "SQUARE ENIX" logo screen.
Settings in x360ce;
Any suggestion for the setting ?