The Tamil Nadu State Transport Corporation (TNSTC), State Express Transport Corporation (SETC), and Metropolitan Transport Corporation (MTC) are three distinct entities that manage public transportation in Tamil Nadu, each serving specific purposes and regions.

1. Tamil Nadu State Transport Corporation (TNSTC):

   • TNSTC is a state-owned transport corporation responsible for operating long-distance and inter-district bus services within Tamil Nadu.
   • It is divided into multiple divisions, such as Chennai, Coimbatore, Madurai, Salem, Tirunelveli, Villupuram, and Kumbakonam, each managing bus services in its respective region.

2. State Express Transport Corporation (SETC):

   • SETC is a subsidiary of TNSTC and is primarily focused on providing long-distance express services between major cities and towns within Tamil Nadu and connecting neighboring states.
   • SETC buses are known for their comfort and are often used for inter-state travel.

3. Metropolitan Transport Corporation (MTC):

   • MTC operates in the Chennai metropolitan area and is responsible for providing bus services within the city and its suburbs.
   • It manages an extensive network of city buses that serve various routes, catering to the local commuting needs of residents and visitors.

Each of these transport corporations has its own set of routes, services, and functions, contributing to the overall public transportation system in Tamil Nadu.