If the labour cost is cheaper than china, it is worth starting a manufacturing unit in india?

Logistics support is still poor in India, so if you have to scale resources to up production, it maybe a problem. Secondly, North India, Govts are unfriendly ( that's why realty, education and healthcare are prevalent, but most is substandard, there even news reports stating electricians earning more and performing better than engineers). My experience has been, target the deccan area for production and produce export oriented units too, because India is geographically well placed with both eastern and western coasts. Secondly if you are focusing on agri based production, then north maybe seen as an option.

Yes it is worth starting a manufacturing unit in India because, One of the major factors tilting the scales in favour of manufacturing in India is favourable movements in the foreign-exchange market. The yuan has climbed7.2 per cent against the US dollar in the past three years and35.3 per cent in the past decade, making China's exports costlier. The rupee, meanwhile, has dropped26.7 per cent in the past three years, making imports more expensive. Rising wage costs in China are playing an equally important role in Indian companies' decisions to shift manufacturing back home. This is particularly true in the case of labour-intensive industries such as textiles and toy making. Wages in China, particularly in coastal areas where most factories are located, are already higher than in India and growing more than10 per cent a year. It's not just labour-intensive, low value-added industries that are moving manufacturing to India. Companies in electrical goods and home appliances are doing so.

Absolutely yes if the laws, the regulation and the implementations are changed and adjusted to be similar to China that attracted that many companies and investors.