Indian Overseas Bank is in Follwing Districts in Tamil Nadu State

Alapuzha
Chennai
Chidambaranar
Chingleput
Coimbatore
Coimbotore
Cuddalore
Dharmapuri
Dindigul
Erode
Kamarajar
Kancheepuram
Kanniyakumari
Kanyakumari
Karur
Krishnagiri
Madurai
Medak
Nagapattinam
Namakkal
Neyveli
Nilgiris
Perambalur
Pudukkottai
Pudukottai
Ramanathapuram
Salem
Sivaganga
Thanjavur
Theni
Thiruvallur
Thiruvarur
Thoothkudi
Tiruchiorappalli
Tiruchirapalli
Tirunelvali
Tirunelveli
Tiruvallur
Tiruvannamalai
Tiruvarur
Toothukudi
Vellore
Villupuram
Virudhunagar