The correct answer is option 3, NandaDevi. Nanda Devi is the highest peak in undisputed Indian territory. Let`s evaluate the other options to understand why they are not the correct answer.
Option 1, Mount Everest, is the highest peak in the world, but it is not located in undisputed Indian territory, as it lies in the border region of Nepal and China.
Option 2, Kanchenjunga, is the third highest peak in the world and is located in the border region of Nepal and India. While it is partially in Indian territory, it is not the highest peak in undisputed Indian territory.
Option 4, Nanga Parbat, is located in Pakistan-administered Gilgit-Baltistan, which is not Indian territory at all. Therefore, option 3, Nanda Devi, is the highest peak in undisputed Indian territory.