The major occupation of the people living in the southern plateau is agriculture.

Reasons:
1. Agricultural Land: The southern plateau region has fertile soil and favorable climatic conditions, which makes it suitable for agriculture. The region receives sufficient rainfall, and the land is well-suited for farming activities, including the cultivation of various crops and the rearing of livestock.

2. Crop Cultivation: The people living in the southern plateau engage in the cultivation of a variety of crops such as rice, wheat, millets, pulses, oilseeds, sugarcane, and cotton. These crops are grown for both subsistence and commercial purposes, providing sustenance and income for the local population.

3. Livestock Rearing: In addition to crop cultivation, animal husbandry is also an important occupation in the southern plateau. The region is known for the rearing of livestock such as cattle, sheep, goats, and poultry. Livestock farming not only provides dairy products like milk, meat, and eggs but also serves as a source of income through the sale of animals and their products.

4. Employment Opportunities: Agriculture in the southern plateau region provides employment opportunities for a significant portion of the local population. Farmers and agricultural laborers work in the fields, cultivating crops, tending to livestock, and engaging in related activities. The agricultural sector also supports other ancillary industries such as transportation, storage, and marketing, creating additional employment opportunities.

5. Traditional Occupation: Agriculture has been a traditional occupation in the southern plateau for generations. The knowledge and skills required for farming have been passed down from one generation to another, and agricultural practices have become deeply ingrained in the local culture and way of life.

6. Economic Importance: Agriculture is the backbone of the economy in the southern plateau region. The production of crops and livestock not only fulfills the local demand for food and raw materials but also contributes to the overall economic development of the area. Agricultural products are not only consumed locally but are also exported to other regions, generating income and boosting the economy.

In conclusion, the people living in the southern plateau primarily depend on agriculture as their major occupation. The region's fertile land, favorable climate, and traditional knowledge have made it a hub for agricultural activities, providing livelihoods and contributing to economic growth.