Critically explain the economic policy prior to 1991, with its achievements and failures.

The answer to this question is already covered in our study material. Follow the given link and scroll down to the topics ' Achievements of planning process in India' and 'Failures of planning process in India' to view the same.

https://www.meritnation.com/cbse/class11-commerce/studymaterial/economics/indian-economic-development/unit-iindian-economy-1950-1990/442_2484_6372#slide6_critical-appraisal-of-planning-in-india-–-achievement-and-failure