Without marketing alliance and codesharing, these flights are expensive to operate. And it does not help that the planes are parked at JFK all day.
But with DL gone (except the one stop former NW route via AMS to BOM), and trimming perhaps to five times a week to DEL and BOM, AND joining the *A, perhaps these flights might still work.
Important thing is AI has to join the *A quickly and for that they have to integrate their website and code share all AI, AIX and IC flights with a single AI code. Now how difficult is that, especially in the land of Informational Technology ?