My maid is travelling with me by air but I only have a photocopy of her ration card as an ID card. Will that be acceptable by airline and airport authority?
It is specifically not accepted as a document of identity or proof residence since April 1, 2016. Source: Government of India. http://passportindia.gov.in/AppOnlineProject/pdf/CBE_0134853_Y.pdf
There are two places that can potentially impact you here- gaining access to the airport and the airline you are flying with. So you should contact them and ask. But it is highly unlikely that a copy will suffice in any circumstance. Air India, for example, specifies a number of cards or documents, the common issue between them all being that they all are original and have a photo:
Note though they do supply the alternative:
In case the Customers do not possess any of the above documents, they should carry a relevant attested document that contains a recent photograph of the traveling Customers.
Attestation is something that can be done by a notary, or a number of other professionals in India, such as teachers or army officers of a certain rank. But for them to attest a copy they are likely going to want to see the original... so you are back to square one.
Presuming it is a domestic flight Indian airlines do accept quite a wide variety of documents, but in most cases they have to be original and they have to have a photo- so attempting to get her some official photo ID might be advisable.