Why are imported Chinese products in India cheaper than those locally produced? Why an imported Chinese product in India is cheaper compared to a locally manufactured item?
Consider an exact same product, say an umbrella, which is both imported from China in India and locally produced. The reason why the Chinese product is cheaper compared to the local one could be related to differences in productivity or total factor productivity. The Chinese product could be relatively cheaper because Chinese firms use better production techniques, 
higher-quality general labor and capital input, better managerial practice/talent, or better information technology. See the JEL survey about What Determines Productivity?

The recent paper by Rodrik and co-authors documents that labor productivity is higher in China than in India (see Table 1). This could be a first reason why prices of the same product differ.