This is what usually happens with authoritarian regimes, I thought you'd know that. They get nervous over everything.
But let's look at the ground realities.
Terrorism Risk Index - Maplecroft
India - Extreme Risk of Terrorism (Highest category)
China - Low Risk of Terrorism (Lowest category)
All the great powers in the past, have been homogenous during their rise to power. Britain, Japan, Germany, and even the USA when they will still a rising power.
It was only after these nations arrived as great powers, that they started to diversify. And even then, even highly diverse Britain is today still 90% white! (You can check it yourself)
India on the other hand, has no majority ethnic or cultural group. It is entirely different from all these other rising powers, and will most likely experience a lot more turmoil during this phase than the others did. The fact that India was born with a Western democratic system is actually a good thing in this situation.