So can you upload sketches to your board, like blink? What are you wishing to do with pin 0 on the arduino?
Yes. I can. But the problem is even the blinky code on any pin say pin 10 works... but still the Tx pin remains at high state...
I am trying to use pin 0 as a normal output pin. and I am not using serial commands... If u ask me will the pin 0 work? it works. because if i explicitly make it LOW if a particular condition is met Pin 0 output becomes zero. But the problem is when its in standy or not doing any operation on pin 0 like in blinky code on pin 13, Tx pin it goes high for no apparent reason.
I even tried setting Output to LOW in the setup function thinking that default value of Pin 0 may be HIGH and I will set it to LOW once in setup so that it low whwn rest of the program runs. but still Tx pin goes HIGH. 
and Currently its showing a voltage of 3.6V.