Google suggests many governments have done it. And they're all linux variants.
Why are you fixating on "Linux variants/forks"? Is there something inherently undesirable about them?
No, it's just that the linked article says that India is going to be designing and developing a completely new architecture, and I'm suggesting that no country has ever done that. And that the likely result will be monstrous cost and time overruns followed by a quick and dirty forking and rebranding of linux to save face.
I don't have a link to the official announcement, so I can't be certain, but I doubt they're going to build their own hardware architecture. It's reasonable to think they will develop a new OS; one can only hope to see an actual OS based on the principles behind Minix, but that's my little dream world there. :-)
It means they didn't actually write the OS themself.