STEP 1. Open a root browser e.g RomtoolBox, SolidExplorer.
STEP 2. Navigate to /etc.
STEP 3. Now open file named Vold.fstab as a Text File.
STEP 4. At the end of the file Paste This Code :
# usb otg disk
dev_mount usbotg /mnt/usbotg auto /devices/platform/mt_usb /devices/platform/musbfsh_hdrc
STEP 5. Now save the file and restart your phone/tablet . And test it by connecting an OTG cable.
There you go. You have successfully enabled OTG on your device. : )