The Namchik-Namphuk Coalfields are located in the state of Arunachal Pradesh, which is Option 1.

Arunachal Pradesh is a state in northeastern India and is known for its rich mineral resources, including coal. The Namchik-Namphuk Coalfields are one of the major coal deposits in the state. These coalfields are situated in the Changlang district of Arunachal Pradesh.

The Namchik-Namphuk Coalfields have significant coal reserves and have been a subject of interest for coal mining activities. The estimated coal reserves in this area are around 133 million metric tonnes. The coal found in these fields is of good quality and suitable for various industrial uses, including power generation and steel production.

The coalfields have been the focus of both state and central government initiatives to promote coal mining and develop the region`s energy resources. The Arunachal Pradesh Mineral Development & Trading Corporation Limited (APMDTCL) has been entrusted with the task of exploring and exploiting the coal deposits in the Namchik-Namphuk Coalfields.

It is important to note that mining activities in the region should be carried out in an environmentally sustainable manner, taking into consideration the ecological sensitivity of the area. Proper regulations and guidelines need to be followed to ensure responsible mining practices and minimize the impact on the local environment and communities.

In conclusion, the Namchik-Namphuk Coalfields are located in the state of Arunachal Pradesh (Option 1). These coalfields have significant coal reserves and are being developed to contribute to the energy requirements of the region while considering environmental sustainability.