Can anyone let me know how to uninstall font from 6600 as i have installed the one and unable to remove. tried removing the new font from manager but the same font stays. please help:)

There was some kind of a font remover app (you can try searching for it), if I remember correctly:
http://www.allaboutsymbian.com/forum/search.php

Otherwise, you can always reformat the device (see the sticky thread on the top of the topic list of this forum).