Depression is inland over central Tamilnadu coast.

12:30pm, "30W" as depression has crossed into central Tamilnadu coast ... near Karaikal.
You can see the center of the system in both the following images.
RADAR image

Visible satellite shot at 12:30pm

pras_ja9:31am via Twitter for Android

@weatherofindia Raining heavily since 6 am in Pondicherry..

10:13am via Web

@weatherofindia The eye of depression is almost over land now. No significant rains or wind in Chennai! Only a persistent drizzle

ImSandeshJain10:14am via Twitter for Android

@weatherofindia Raining very heavily. Chennai South. #Velachery

joesat10:22am via Plume for Android

@weatherofindia #palavakkam 10 am Consistent showers and temperature is down at least 2 degrees than normal

jj_clinton10:27am via Twitter for Android

#Ramanan is right this time..been raining here (chennai sholinganallur) since strday ngt..now some heavy showers..!! @weatherofindia

ensabraham12:16pm via Mobile Web (M2)

@weatherofindia
12:10pm Its raining in Perundurai,Erode,Tamil Nadu..

1:15pm, the Northern band of the Depression is giving heavy rain to Mahabalipuram coast, Vandavasi and madurantakam belt of Tamilnadu.

Heavy and widespread rain ahead for Nilgiris, N-W,central,N Tamilnadu and into S Andhra, S Karnataka during next 18hrs.

#Chennai - will continue to get passing moderate intensity showers during next 24hrs.