Hi Kanimozhi Thangappan ,
The default image build for imx6ULL with GUI has matchbox utility to display the various applications on GUI. The default application that runs is console, which is you see Linux console on LCD. You can play video and run the GUI application which will be displayed on the LCD.
You can also try to add QT to build QT applications and display on LCD as suggested by Rita in the above comment.
Regards,
Karan Gajjar