It’s so well hidden that it’s been discussed on the floors of the US Congress, UK parliament, and between the Indian head of state and his UK/US counterparts.
I find it fascinating that people write comments where their own evidence disproves their comment. Neither of the articles you link to even mention hidden mass deaths, and the articles’ very existence only goes to prove the point that it’s hard to hide info in India.
That’s not to say that China has been hiding a mass of dead bodies that hasn’t been reported. However, it would certainly be a lot easier to do that in China than in pretty much anywhere else in the world, especially India.
I am an Indian, and let me tell you, if 10 people die, its a huge news. Its not possible to cover up anything in India.
You might point out about Kashmir, but Kashmir is a different case considering it had its own constitution and governance until very recently, and due to Pakistan sponsored terrorism, the state has stricter controls than the rest of India.