On the basis of the size of the watershed, the drainage basins of India are grouped into three categories. Which of the following is not one of them?

On the basis of the size of the watershed, the drainage basins of India are grouped into three categories: - Major river basin, medium river basin, and minor river basin. The major river basin has a catchment area of 20000 sq. km and above, the medium river basin has a catchment area of 2000-20000 sq. km and the minor river basin has a catchment area of less than 2,000 sq. km.