Android has access to USB Host mode and the USB hardware is actually capable of USB-OTG (meaning that it can act as both host and peripheral).I bought a Micro USB male to USB-A female cable(USB OTG cable only) from Flipkart. Now I can connect my keyboard with tablet computer using it. Once is connecting the keyboard(wired and wireless with NAND receiver) using OTG cable. And my tablet computer detects it as a keyboard input device.

Now, I can type using a keyboard with a tablet. Also, Android supports few keyboard shortcuts.

PS: Bluetooth keyboard just works fine by configuring it to the tablet computer under Bluetooth settings.