How is South India producing more rice than wheat?

You have the answer (sort 0f) in your question. Rice cultivation requires more water than wheat. On an average, southern and eastern part of India gets more rain per year compared to parts of northern India. read more

However, you might want to know that north India produces more rice and wheat compared to south India, and the reasons could be many (soil composition, temperature pattern and availability of water throughout the year, number of farmers, and area available for cultivation in north vs. south). read more

The Asian continent dominates in terms of global rice production, with China and India leading the way. A farmer weeds his rice paddies in the Indian state of West Bengal. Rice has long dominated the farmlands throughout much of South and East Asia. read more