The correct answer is option 1: Nagpur.

Koradi Thermal Power Station is located in Nagpur, Maharashtra, India. It is a coal-based power plant and is operated by Mahagenco (Maharashtra State Power Generation Company).

Option 2: Raipur is incorrect. Raipur is the capital city of Chhattisgarh, India, and does not host the Koradi Thermal Power Station.

Option 3: Mumbai is incorrect. Mumbai, also known as Bombay, is the capital city of Maharashtra, India. It does not have the Koradi Thermal Power Station.

Option 4: Secunderabad is incorrect. Secunderabad is a city in the state of Telangana, India. It does not have the Koradi Thermal Power Station.

It is important to note that in multiple-choice questions, the correct answer can only be determined by evaluating each option individually. In this case, the correct answer is Nagpur as it is the actual location of the Koradi Thermal Power Station.