I know it's not specifically what you're looking for, but one of the nicest prototypical fan-made settings I've seen is the IR's Darjeeling Himalayan Railway. The route used to be downloadable from
the Trainz Darjeeling Himalayan website but I see they've moved it to the Download Station. Makes for a smoother installation but it does mean that downloading it will take days, possibly weeks, unless you buy a subscription. That's a choice made by the group that made the route, though, so please don't blame the big mean software developers.
(Now, we can talk about the big mean software developers' unreasonable download throttling, or the way I came away from their website under the impression that DLS would only be slower for unpaid users instead of totally unusable... but that's for another thread.)
I was going to suggest that part of the issue might be that nobody wants to work on trains meant for Broad Gauge when something made for Standard Gauge can fit in with so many more layouts. But even though there's a pretty reasonable following for narrow gauge stuff, Indian Railways equipment on Metre Gauge isn't well represented either, so I'm probably wrong on that.
Ultimately, it comes down to this: the people who are volunteering their own time to develop content for fun are developing the things they're interested in. For me, I have an interest in "short line" freight services in North America, so that's what I'm working on.
Mate if i can make the model then why will ask auran to make one..
Me neither, so in order to create the content I'm interested in, I'm learning.
I was gonna say that I liked that Indian diesel, reminded me a bit of some of the later Alco RS series... turns out they're cousins! The WDM3A you posted a video of is an evolution of the WDM2, built in India but prototyped by Alco a few years after the similar looking RS-11, both of which have a reputation for being versatile and reliable... though it seems the Indian-built ones have long outlasted Alco's own! Nice!