HDFC Bank is in Follwing Districts in Tamil Nadu State

Chandauli
Chennai
Coimbatore
Coimbotore
Cuddalore
Dharmapuri
Dindigul
Erode
Kancheepuram
Kanchipuram
Kanniyakumari
Kanyakumari
Karur
Krishnagiri
Madurai
Nagapattinam
Namakkal
Nilgiris
Perambalur
Phoothukkudi
Pondicherry
Pudukkottai
Ramanathapuram
Salem
Serilingampally
Sivaganga
Thanjavur
The Nilgiris
Theni
Thiruvallur
Thiruvarur
Thoothkudi
Tiruchiorappalli
Tiruchirapalli
Tiruchirappalli
Tirunelvali
Tirunelveli
Tiruppur
Tiruvallur
Tiruvannamalai
Tiruvethipuram
Toothukudi
Tuticorin (thoothukkudi)
Vellore
Villupuram
Virudhunagar