Originally Posted by mm84321
I'd say swiss chard or spinach would be an acceptable substitute. Collard greens have a much different texture than any of these.
This is true, but if he is trying to make a classical indian style dish then collard greens are not used at all. Totally different texture and I'd just sub in spinach instead. Although, that won't provide the same flavor.
To the op: I see that you are in princeton, look for some asian supermarkets around the rt 1/27 area. There should be some indian grocery stores there as well.