Cuddalore, also spelt as Kadalur, is a heavy industries hub and a port city, and headquarters of the Cuddalore District in the Indian state of Tamiā¦Cuddalore, also spelt as Kadalur, is a heavy industries hub and a port city, and headquarters of the Cuddalore District in the Indian state of Tamil Nadu. Situated south of Chennai, Cuddalore was an important city and port during the British Raj.