The statement "The Gross Domestic Product (GDP) has increased by four times in the last 10 years" is incorrect. The Indian economy has not grown by four times in the last 10 years. However, the economy has grown at a steady rate during this period, with an average growth rate of around 7% per annum.

The statement "The percentage share of Public Sector in GDP has declined in the last 10 years" is correct. The share of the public sector in the Indian economy has declined in the last decade, as the government has undertaken measures to liberalize and privatize the economy. This has led to an increase in the share of the private sector in the economy. As of 2021, the public sector accounts for around 25% of India`s GDP.