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- (Namakkal) Odappālaiyam
- (Namakkal) Olaippatti
- (Namakkal) Ottakulampudūr
- (Namakkal) Ottaiyūr
- (Namakkal) Odakkattūr
- (Dharmapuri) Odachchālpatti
- (Dharmapuri) Odduppatti
- (Salem) Ottukkādu
- (Salem) Oddappatti
- (Salem) Olaippadi
- (Namakkal) Oyanguli
- (Namakkal) Odakkādu
- (Salem) Odavankādu
- (Salem) Odiyattūr
- (Salem) Oddappatti
- (Tiruchirappalli) Okkarai
- (Tiruchirappalli) Oddanpatti
- (Villupuram) Olagadaiyāmbattu
- (Villupuram) Olagamkāttān
- (Villupuram) Olagiyanallūr
- (Cuddalore) Orangūr
- (Perambalur) Odiyam
- (Tiruchirappalli) Orattūr
- (Tiruchirappalli) Oduvampatti
- (Salem) Odaikkādu
- (Tiruchirappalli) Osarappalli
- (Thoothukkudi) Ottapidaram
- (Thanjavur) Orathanadu
- (Kancheepuram) Oragadam
- (Tiruchirappalli) Omandur