Coastal Tamil Nadu is bracing for heavy downpour and strong winds midweek.
Cyclone Nivar is expected to make landfall along coastal Tamil Nadu and Puducherry on Wednesday.
The IMD has issued a red alert for the two places.
A yellow alert has been issued for coastal Andhra Pradesh and Telangana.
After Cyclone Gaja in 2018, this is the second cyclone to cross Tamil Nadu.
Extreme weather conditions would occur both on Tuesday and Wednesday.
Winds with speed 100 to 120km/hr are expected for at least 12 hours on Wednesday.
Sea conditions will also be most unfavourable.
Tidal waves up to one metre are expected, which could inundate low-lying areas.
Fishermen have been advised not to venture into the sea for the next three days.
Power and communication lines could also be affected.
PM Narendra Modi has assured all possible support to the chief ministers of Tamil Nadu and Puducherry.