Enabling OTG support in Micromax Canvas Nitro A310
Rooting alone does not enable USB OTG functionality.  Rooting (and having an unlocked bootloader) only allows you to flash a custom kernel that is built with proper support for USB OTG on your specific device.
OTG API has been included in Android since version 3.1.  Many modern Android devices have the necessary hardware as well.
USB OTG software alone without the proper hardware won't help at all.
There are many apps on the Play Store that claim to be able to tell if your phone supports (both hardware and software wise) OTG functionality, but most of these apps also require root.