Indian SFs (at least the mainstream units like Para SF) never train with JSOC Tier-1, which are the ones who chiefly use the -18s. We trained with Tier-2 units like Rangers, Green Berets etc and far as I know, there are no Tier-2 users of -18s. So highly unlikely Paras ever even came into contact with -18s.
The capability set provided by the -18s is not likely to be very relevant for a Tier-2 style force which principally does support for Tier-1s as part of QRFs or otherwise required for long-duration overland maneuvers. So the likes of Rangers prefer the smaller, lighter PVS-31s and such.
So while we can't conclusively say what the model of NVGs being sought are, I think personally I'd lean heavily toward aforementioned PVS-31. And if it were to be White Phosphor-based, I'd be overjoyed.