The concept of a Five Year Plan in the Indian Constitution was borrowed from the USSR (Union of Soviet Socialist Republics).

Explanation:

The concept of Five Year Plans was first introduced by the Soviet Union in 1928, with the aim of rapidly industrializing and developing the country's economy. The plans involved setting specific targets for various sectors of the economy, such as agriculture, industry, and infrastructure, and allocating resources accordingly to achieve these targets within a five-year time frame.

In the Indian context, the idea of Five Year Plans was incorporated into the Constitution to ensure planned economic development and equitable distribution of resources. The Indian Constitution, adopted in 1950, included provisions for economic and social planning in the Directive Principles of State Policy. These principles, enshrined in Part IV of the Constitution, are non-justiciable in nature but serve as guidelines for the government in formulating policies and legislation.

The idea of incorporating Five Year Plans into the Indian Constitution was proposed by Jawaharlal Nehru, who was deeply influenced by the socialist principles of the USSR. Nehru believed that planned economic development was crucial for uplifting the masses and reducing poverty in India.

The first Five Year Plan in India was launched in 1951 under the guidance of the Planning Commission, which was established to formulate and implement the plans. The Planning Commission was responsible for setting targets and allocating resources for various sectors, and it played a key role in shaping India's economic policies for several decades.

The Five Year Plans in India aimed to achieve self-sufficiency in food production, promote industrialization, reduce poverty and unemployment, and improve the standard of living. Each plan focused on specific areas of development and implemented various policies and schemes to achieve the desired goals.

Over the years, the Five Year Plans in India have evolved and adapted to the changing socio-economic conditions of the country. In 2014, the Planning Commission was replaced by the NITI Aayog (National Institution for Transforming India), which functions as a think tank and policy advisory body.

In conclusion, the concept of a Five Year Plan was borrowed into the Indian Constitution from the USSR. It was introduced to ensure planned economic development and has played a significant role in shaping India's economic policies and development strategies over the years.