As of yesterday (11.11.2021), Scattered heavy to very heavy with isolated extremely heavy rain is likely to occur over Chennai, Tiruvallur, Kancheepuram and Ranipettai districts of Tamilnadu. Heavy to very heavy rain is likely to occur at a few places over Vellore, Tirupattur, Tiruvannamalai, Villupuram and Chengalpattu districts of
Tamilnadu. Heavy rain is also likely to occur at isolated over Krishnagiri, Erode, Salem, Dharmapuri and
Kallakurichi districts of Tamilnadu

Thunderstorm with heavy rain is likely to occur at isolated places over Nilgiris, Coimbatore and Kanyakumari districts of Tamilnadu.
Light to moderate rain is likely to occur at many places over rest Tamilnadu, Puducherry & Karaikal area

Reference: http://imdchennai.gov.in/tn_fc.pdf
http://www.imdchennai.gov.in/hrw_district.htm