Explanation:

The agricultural sector has used the highest percentage of total water in India.

Reasons:

1. Agriculture is the largest consumer: Agriculture is the primary sector in India, and it is heavily dependent on water for irrigation. As a result, it consumes a significant portion of the total water available in the country. According to reports, around 80% of the total water consumption in India is used for agricultural purposes.

2. Water-intensive crops: India is known for its cultivation of water-intensive crops such as rice, sugarcane, and wheat. These crops require a substantial amount of water for their growth and development. As a result, the agricultural sector needs to use a significant amount of water to meet the irrigation requirements of these crops.

3. Lack of efficient irrigation techniques: The agricultural sector in India still relies heavily on traditional irrigation methods such as flood irrigation, which are not very efficient in terms of water usage. These methods often result in a wastage of water, further increasing the overall water consumption in the sector.

4. Large agricultural land: India has a vast agricultural land area, which contributes to the high water consumption in the sector. The agricultural activities across the country require water for irrigation, leading to a higher percentage of total water usage.

5. Dependency on monsoon: India's agricultural sector heavily relies on monsoon rains for irrigation. In regions with inadequate rainfall, farmers often resort to groundwater extraction through tube wells and borewells, which further increases the water consumption in agriculture.

In conclusion, the agricultural sector in India has used the highest percentage of total water due to its large consumption for irrigation purposes, the presence of water-intensive crops, the reliance on traditional irrigation methods, the extensive agricultural land, and the dependency on monsoon rains.