LoL! Those sore losers. China is a problem for them because it stands in the way of their fictional Akhand Bharat. They want Kashmir, but China backs up Pakistan. They want Tibet, but it actually is Chinese territory. They want Xinjiang but it is also Chinese territory. They want the other South Asian nations, but China is better friends with them than India. China is a real nation that has been built over thousands of years. But India is an artificial nation setup by the British, only established in 1947. China is a real civilizational state, while India is a post-colonial construct. India considers itself a first-world Empire, but "lowly" China beats India by every human development metric.
The more they want to question about One China, the more they invite scrutiny over the myth about what India actually is. This Air Force Marshal fella and many other Jai Hinds claim that Tibet and Xinjiang are culturally closer to India. Again, what is India actually? India had never even existed when Tibet and Xinjiang were already part of China.
If they truly want to take Tibet and Xinjiang from China, then bring it on. The PLA's Western Theater Command shall greet them. If they want to play with Taiwan, then China can also play with India's North East and Kashmir. Let's see who can do more damage.
LOL! Then by that logic, Xuanzhang's journey to India means that China can lay claim to any part of India that he had been, which is practically all of India. So India already belongs to the Tang Dynasty, and by extension, its successor, the PRC. That's the power of Jai Hind logic. BTW when Xuanzhang visited India, it wasn't even called India. It was a actually a region made up of empires and kingdoms. There was definitely no Akhand Bharat in sight in when he was there.