Depending on the extent of coronavirus pandemic, the Central Government of India listed each district in the country as red, orange, and green zones. In that List, 12 Districts of Tamilnadu came under Red Zone, 24 Districts in Orange Zone, and 1 in Green Zone.
Red Zones in Tamilnadu: Chennai, Madurai, Namakkal, Thanjavur, Chengalpattu, Thiruvallur, Tiruppurm Ranipet, Viruthunagar, Tiruvarur, Vellore and Kanchipuram
Orange Zones in Tamilnadu: Theni, Tenkasi, Nagapattinam, Dindigul, Villupuram, Coimbatore, Cuddalore, Salem, Karur, Tuticorin, Trichirappalli, Tirupathur, Kanniyakumar, Tiruvannamalai, Ramanathapuram, Tirunelveli, Nilgiris, Sivagangai, Perambalur, Kallakuruchi, Ariyalur, Erode, Puthukottai, and Dharmapuri
Green Zone in Tamilnadu: Krishnagiri