We could quibble about the details, but all of them are fundamentally last-man-standing competitions.
The Hunger Games was indeed one of them. I didn't mention it because it's the most obvious one in current cultural memory (no need for me to point it out) and because Battle Royale came a decade earlier, and Battle Royal half a century before that. The characters' situation is probably older than printed words.
Even if a competitive game format was unique to the Hindi film, it would be tough to argue that nobody else could have thought of that detail when making their own variation of the same theme. Calling it a "blatant rip-off" of Luck (2009) is quite a stretch.
(Incidentally, the Luck synopsis that I read says it focuses on gambling, not competitive trials or children's games. A quick look at the video confirms it.)
nobody's saying either wrong is right. nobody's blaming the one dude.
as an indian, i've always cringed at movies like baazi, kaante, aatank hi aatank, hum tum, chachi 420, zinda, ek ruka hua faisla, satte pe satta, sholay, qayamat, ghulam, and a boatload of other shameless rip-offs and i was just marvelling at the irony of the situation.