definitely a cage. I suspect it previously housed a cat or dog species. To the left (the big rusting cage) is "proposed enclosure for wolf"; to the right is the edge of the striped hyaena cages.
I have no idea why they don't have the emus in one of the paddocks...
I've only been to three Indian zoos (in Mumbai, Calcutta, and Guwahati). The last one didn't have emus, and the first two both kept them in cages. I may make it to Delhi Zoo later in this trip but that will be it.