There are as yet no clearly defined laws regarding drone registration and use, but there are regulations depending on what the drones are to be used for. Commercial use such as mapping or surveys might require permission and permits from relevant departments for the region in which the surveys are to be conducted. It's recommended that you use a locally registered company to get these permits as the process will be drastically shortened. A written application would have to be submitted to the department to attain permission.
Foreigners are permitted to fly drones for recreational purposes so long as you stick to safe zones and away from restricted areas. In the case of filming and/or surveys, surveillance or mapping, permits would be required.
Drones are allowed into the country through the airport but must be declared upon entry.