In order to hard reset a Micromax A57 Ninja 3.0, you should perform the following steps.
Remember! Hard reset will delete all the data on your device; pictures, contacts, messages, apps and more.
Micromax A57 Ninja 3.0 device will be brought back to the default configuration of a brand new device.
1. Power down the phone.
2. Press'n'hold the Volume Up & Power buttons until a Recovery mode menu appears.
3. From that menu, select the wipe data / factory reset option.
4. Next, select Yes -- delete all user data and reboot system now.
5. Done.