The correct answer is option 4, Tawi. Tawi is not a tributary of the Indus River. A tributary is a river or stream that flows into a larger river, and in this case, we are looking for the river that does not flow into the Indus River.

Option 1, Beas, is a tributary of the Indus River. It originates in the Himalayas and flows through the states of Himachal Pradesh and Punjab in India before joining the Indus River.

Option 2, Ravi, is also a tributary of the Indus River. It originates from the Bara Banghal range in Himachal Pradesh, India, and flows through Punjab before merging with the Indus River in Pakistan.

Option 3, Chenab, is another tributary of the Indus River. It is one of the longest rivers in the region and flows through the Indian states of Jammu and Kashmir and Himachal Pradesh before entering Pakistan and joining the Indus River.

Therefore, the correct answer is option 4, Tawi, as it is not a tributary of the Indus River.