The correct answer is option 2, Soviet Union. Bokaro Steel Limited was established with the assistance of the Soviet Union. The Soviet Union provided technical and financial support for the establishment of the steel plant in Bokaro, located in the present-day state of Jharkhand, India.

The Soviet Union played a significant role in many industrial projects in India during the Cold War era. In the 1960s, when India was aiming to expand its steel industry, the Soviet Union offered its expertise and assistance. Bokaro Steel Limited was one of the outcomes of this collaboration.

The Soviet Union`s assistance helped in setting up the infrastructure and technology required for the production of steel. They provided technical experts, equipment, and financial aid to ensure the successful establishment of the steel plant.

It`s important to note that while other countries like Germany, UK, and USA have also made significant contributions to India`s industrial and economic development, the correct answer in this particular case is the Soviet Union.