1- Charge your Micromax Canvas 4 A315 upto 70 percent.
2- Switch off your mobile.
3- Press & Hold Power+Volume up+Volume down.
4- Android logo with red exclamation mark appears.
5- Now press Power key to enter recovery mode.
6- Select Wipe Data/Factory reset using Volume key and Power to enter.
7- Choose Yes-delete all user data and enter through Power key.
8- Select Reboot system now.
9- Now, you mobile is free from pattern lock and has been reset to default.