At least 88 of the deaths took place in the Maharashtra state's capital Mumbai, also India's financial capital, the state's deputy chief minister RR Patil said on Thursday.
Meanwhile, the Maharashtra state police control room said 157 people had died in wall collapses, landslides and drownings in other parts of the state, which has been lashed by monsoon rains since Monday.
"Another 200 people are feared dead across the state," said an official in the control room.
The torrential rains had eased on Thursday, but skies remained overcast and more rain was forecast.
"Moderate rains are expected in the city on Thursday while heavy rains are expected in the suburbs," a weather official said.
The city's weather bureau said Mumbai received 944.2 millimeters of rainfall in a 24-hour period ending mid-morning on Wednesday, the most rainfall ever recorded in a single day in India and beating a record which has stood since July 1910.
Aerial pictures of Mumbai telecast by the Hindi news channel Aaj Tak showed large parts of the city marooned in debris-laden water.
Long queues of cars, trucks and other vehicles were seen stranded on main arteries and highways linking different parts of the city.
Schools in Maharashtra, which closed on Wednesday, remained shut while banks and stock markets were also closed on Thursday.
Authorities were air dropping food and water to stranded residents of Mumbai and Raighad district, about 170km south of the city, Aaj Tak reported.