To convert these rainfall rates to total daily rainfall, each 3-hourly rr are multiplied by 3 hours, to get the total rainfall for each 3-hour period. Then, for your desired 24-hour-day begin and end times, sum all the 3-hourly total rainfalls in your defined 24-hour period, to get the total daily rainfall
However, some parts of India receive considerable rainfall during the pre-monsoon (March to May) and postmonsoon seasons (October to December).