At the national level, which ministry is the nodal agency to ensure effective implementation of the Scheduled Tribes and Other Traditional Forest Dwellers (Recognition of Forest Rights) Act, 2006?

The correct option is Ministry of Tribal Affairs.

Step-by-Step Explanation:

1. Understanding the Act:
The Scheduled Tribes and Other Traditional Forest Dwellers (Recognition of Forest Rights) Act, 2006 (commonly known as the Forest Rights Act or FRA) was enacted to recognize and vest the forest rights and occupation in forest land in forest-dwelling Scheduled Tribes (FDST) and Other Traditional Forest Dwellers (OTFD) who have been residing in such forests for generations.

2. Identifying the Nodal Ministry:
At the national/central level in India, the administrative and nodal responsibility for the welfare, development, and implementation of laws specifically protecting the rights of Scheduled Tribes lies with the Ministry of Tribal Affairs.

3. Role of the Nodal Agency:
The Ministry of Tribal Affairs issues guidelines, oversees implementation, monitors progress, and clarifies rules associated with the Forest Rights Act, 2006 to ensure forest-dwelling communities receive their legal rights over forest land and resources.

Thus, the Ministry of Tribal Affairs is the nodal agency responsible for its effective implementation.