I need to show the task bar on top of a full screen page opened by google chrome browser? is it possible? i tried to search but no results were found.
Alt+F11 if on windows keyboard connected directly or remotely to the Raspberry Pi. If using Mac to connect remotely (via VNC or similar remote control), try
Opt + F11 or
Fn + Opt + F11.
This combination toggle full-screen mode on or off and will therefore make the browser window that is hiding the taskbar become a normal window again and show the taskbar.
The above assumes i understand your question correctly, meaning on startup of the RPi, a browser window set to ran at startup is coming up in full screen mode and does have window control (to close it) and in addition, is hiding the taskbar and withit the RPi menu.