Is post office ID card accepted as ID proof for flight to travel withinin India? What else other than PAN card, driving license is accepted as ID? Where do I need to show it?
Any government issued ID should be fine, but PAN or passport is the most widely used. You will need to display the ID at airport security as well as the airline check in counter.
Many airlines provide a list of accepted ID cards and, as far as I remember, the Post Office card is not explicitly mentioned by any one of them. However, its the airport security (CISF) which checks the ID and not the airlines. Also, there is some variation in the list of acceptable IDs given by different airlines.
I believe that almost any photo ID card including the Post Office card should work fine. A couple of years ago, I had used a photo credit card without any problems.
For more details, check the list of IDs at the following websites: