The 47 people were rescued from Limpopo province, Xinhua reported citing police official Brigadier Hangwani Mulaudzi. All the victims were from Ethiopia, and were in good health, he said.
The six arrested include and Indian and five Ethiopians, he said. Their identities were not known.
A recent UN report titled "Global Report on Trafficking in Persons" by the UN Office on Drugs and Crime (UNODC), based on data gathered from 155 countries, says the most common form of human trafficking (79 percent) is sexual exploitation.
Surprisingly, in 30 percent of the countries which provided information on the gender of traffickers, women make up the largest proportion of traffickers.
In some parts of the world, women trafficking women is the norm, the report said.
The second most common form of human trafficking is forced labour (18 percent). The report, however, said forced labour was less frequently detected and reported than trafficking for sexual exploitation.
Worldwide, almost 20 percent of all trafficking victims were children. In some parts of Africa, children were the majority, it said.