The Bulls said Nkosi, who has played 16 tests for South Africa and was part of the squad that won the 2019 World Cup, last made contact with any executive, management or playing squad member on Nov. 11.
The team lodged a missing person case with police and Nkosi was found after "lengthy and extensive efforts" at around 1402 local time on Monday.
"Once it was established that Nkosi was safe, unharmed and in a position to speak, Chief Executive Edgar Rathbone went into Nkosi's home (with the permission of the player)," the team said in a statement.
The Bulls added that Rathbone spent time with the player to understand "how best they can provide him with the support he needs and what that support is."
The club added that they could not give more information about the matter but would hold a news conference on Tuesday.
Nkosi was named in South Africa's squad for tests against Ireland, France, Italy and England in November but was ruled out of the autumn internationals after suffering a rib injury while playing for the Bulls in the United Rugby Championship.
