Step 1: Recall the National Green Tribunal.
The National Green Tribunal (NGT) was established under the National Green Tribunal Act, 2010 as a specialized judicial body in India.
Step 2: Identify its mandate.
The NGT was specifically created for effective and speedy disposal of cases related to environmental protection, conservation of forests, and safeguarding other natural resources. It also enforces legal rights relating to the environment and gives relief and compensation for environmental damage.
Step 3: Eliminate incorrect options.
Fisheries management, election disputes, and general civil matters are handled by entirely different forums.
\[ \boxed{\text{Environmental protection and conservation of forests and natural resources}} \]