The fire broke out in the office of a private bank around 10:30 am, the reason for which is yet to be ascertained, they said.
Ten to 12 fire tenders, including some from Army and Navy, were used and the fire was doused after over one-and-a-half hours.
A majority of the people were taken to safety by fire force personnel and locals who rushed to the spot to assist in rescue operations, District Collector M Karunagaran said.
There are eight offices in the complex employing 300 people.