The government also said those passengers from the 12 regions have to be in home isolation for seven days and on their eighth day of arrival have to undergo another RT-PCR test.
According to the government, the passengers then have to monitor their health for another seven days.
Those who have contracted the virus will be treated in government hospitals and their samples will be sent for genome sequencing to check for any virus mutation.
The region and countries are Europe including UK, as well as South Africa, Botswana, Hong Kong, China, Israel, New Zealand, Zimbabwe, Singapore, Brazil, Bangladesh, and Mauritius.
Tamil Nadu government also said passengers from the above countries showing Covid-19 symptoms should have to inform the primary health centres or call 104 and inform and those who were in contact with them will have to be traced and treated.
In the case of flights from other countries, five per cent of the passengers will have to undergo RT-PCR test.