The Indus Water Treaty of 1960 is an agreement between India and Pakistan that governs the sharing of water from the Indus River system. According to the treaty, the rivers under its purview are the Indus, Jhelum, and Chenab.

Option 1: Ravi - The Ravi River is one of the six main rivers in the Indus River system. It flows through India and Pakistan and is included in the Indus Water Treaty. Therefore, option 1 is not the correct answer.

Option 2: Chenab - The Chenab River is also one of the main rivers in the Indus River system. It flows through India and Pakistan and is covered under the Indus Water Treaty. Therefore, option 2 is not the correct answer.

Option 3: Teesta - The Teesta River is not a part of the Indus River system. It flows through India and Bangladesh but does not fall under the jurisdiction of the Indus Water Treaty. Therefore, option 3 is the correct answer.

Option 4: Beas - The Beas River is one of the five rivers in the Indus River system. It flows through India and is also covered under the Indus Water Treaty. Therefore, option 4 is not