Where can I find Mi3' s phone and SMS ringtone?

Setting the ringtone as an incoming call can be achieved through software, MIUI music, beautiful daily life and so on. Copy the music file to the /MIUI/ ringtone folder, and open Settings-Sound and Vibration-ringtone. You can choose the music file you just added as the ringtone and put it in the notification folder under the root directory of SD card. Similarly, you can set SMS ringtones.