To be honest the sad part is that these investments will not make a big difference in employement.
Almost all car factories in India/world are robotic and mechanized.
India's rigid and archaic labour laws, downright pathetic - thanks to our socialist past - further encourage all companies to use more mechanization rather than hiring more workers. This is the reason why India's growth is more capital intensive than labour intensive.
The backbone of labour hiring in India are the SME - Small and Medium Enterprises - not these global factories.
And unless and until we repeal and modify these labour laws, India will continue to have employement problems.
This big industries requires multiple smaller ones. A car factory would requires several smaller factories to manufacture parts. A service industry, not to mention the flow of money in the economy.