According to the import and export country reports on the website of China's Ministry of Commerce.
The top category of India's exports to China in 2017 was minerals, accounting for 26%. The top category of imports from China was machinery, electronics and electrical appliances, accounting for 56 percent.
For the more technologically advanced categories, the top three, mechanical and electrical, transportation equipment, and optical and medical equipment, China's exports to India amounted to 32 times more than imports from India. And that's even with their desperate rejection of Chinese manufacturing.
India's exports of industrial goods have a share of the world's trade market close to what China's was in 1980.
So in short, why India is poor is because industry is not competitive. Their trade relationship with China is that they sell us ore and then we manufacture it into products and sell it back to them. Interestingly, if one looks at India's industrial exports over the years, one can see that their industrial competitiveness is in decline.