Can I directly connect XBee module over WLAN ?

I have a device that currently works over serial communication. Whenever I transmit code over serial cable I get a response from the device.

I have able to convert this wired serial communication wireless using a bluetooth SPP module.

If I use a XBEE module with this device and make it wireless then can I connect the module over WLAN for my operations or will I be requiring another XBEE transceiver at other/PC end to complete flow.

If I understood your question correctly, you will need another XBEE module. XBEE cannot connect directly to WLAN (by this I assume you mean Wifi).

Maybe something like an RN-171 (WiFi module) will be better suited, just keep in mind depending on the module it may not be a direct cable replacement, i.e. you would have to send it some commands (usually AT commands) to configure it and get it to connect. (On some modules - like XBEE - you only have to do this once.)

Good Luck...