Cyclone Nivar is expected to make landfall along Tamil Nadu coast on Wednesday evening.
The state has already shifted 24,166 people from low-lying areas to 987 relief centres.
IMD said Nivar is expected to cause structural damage, uproot trees and destroy crops.
Puducherry and Tamil Nadu are expected to take the brunt of it.
The cyclone will be accompanied by a wind speed of 120-130kmph, gusting up to 145kmph.
While Tamil Nadu has declared a public holiday on Wednesday, Puducherry has imposed Sec 144 for three days.
Nearly 1,200 NDRF rescue personnel have been deployed in Tamil Nadu, Puducherry and Andhra Pradesh.
Nivar is the second cyclone in the Bay of Bengal this year after Amphan.