Identify the odd word from the given options.

Agartala, Kohima, and Aizawl are capital cities of Indian states:

Option (a): Thimpu → Bhutan

Option (b): Agartala → Tripura

Option (c): Kohima → Nagaland

Option (d): Aizawl → Mizoram

Thimpu is the capital city of Bhutan, which is a foreign country, not an Indian state.

Hence, Thimpu is the odd one out.

Thus, the correct option is (a) Thimpu.​