Although India's economic development depends upon the amount we get from Foreign Direct Investments-FDI, it won't be a right decision to allow 100% FDI in all sectors.
In 1991 during the phase of economic crises , economic liberalisation started in India for the first time. Due to liberalisation, Foreign companies allowed to invest in Indian industrial sectors. Because of the FDI only unemployment problem during those days was reduced subsequently. Our GDP and PCI were also started increasing. Information technology started booming and Indian software engineers were on great demand.
According to financial times in 2015, India ahead of China and US as the favourable destination for FDI. FDI is allowed in India either by automatic route, where there is no need for government or RBI approval, or by government route, where government approval is necessary.
In 2014, after the launching of Make in India project, Government of India relaxed the norms for FDI in 25 sectors. In August 2017 more sectors were allowed in 100% FDI in automatic route. Some of the sectors are agriculture, plantation, mining, Petroleum Natural Gas, defence manufacturing, broadcasting, civil aviation construction development etc.
Some of the sectors which have less than 100% FDI are Banking public sector 20%, insurance 49%, pension 495, power exchanges 49%.
FDI is prohibited in the following sectors - Gambling and betting, Lotteries chit funds, Nidhi companies, real estate, manufacturing of cigars and so on.