> ... ihave used a print statement inside the interupt handle ...
Which is almost always a bad idea.
Check the implementation of of the debug print function, it surely messes up the timing of your application, blocking other interrupts because it uses interrupts itself.
> ... the Ic Generates an interupt the mcu doesnt process the interuppt but when using test case using software to check the interupt handler it works but when the pin goes from high to low but there is no interupt happening. can anyone explain why it is not working.
Probably not, because your description is not very comprehensible.
Either try to validate your code in steps, as a stop in the debugger most probably breaks up the sequence.
Or, when trying in real-time, take care not to modify the application timing, as debug prints will surely do.
