I doubt that Mani Shankar Aiyar is shilling for the Chinese.  On the contrary, based on his comments in this article, I suspect that he really believes that the only way persuade/encourage/bribe these (sometimes violently) independence-seeking peoples into accepting Indian sovereignty over them is by improving their economic and material well-being through infrastructure development.  Maybe he thinks that the CCP's strategy for assimilating and integrating Tibet and Xinjiang into the larger state will actually work:

Mr Aiyar, a close associate of slain premier Rajiv Gandhi, criticised successive Indian governments for the "complete neglect of infrastructure development" in Arunachal Pradesh, saying that its absence was "much to the disappointment of the people over there".

Or maybe it's the FT journalist who is working for the CCP:

Indian visitors to Tibet are struck by the modernisation that has taken place in Lhasa, the region's capital, road building projects and a high-altitude railway link to China's main network. <...>

A member of parliament from India's northeastern state of Meghalaya, however, said China made itself felt across the border not with its physical infrastructure or military might but by a flood of highly competitive consumer goods. He said cheap Chinese goods were freely available; imported telephone accessories were being sold at a tenth of their Indian equivalents.

But a scan of his previous writings does not suggest a clear pro-China tendency, at least to me.  He does add:

This is in spite of their [Indian visitors to Tibet] reservations about Beijing's erosion of Tibetan culture and Buddhist religious practice.