The 26-year-old goalscorer is a highly-rated striker, who helped Simba clinch the 2017/18 Tanzanian Premier Soccer title.
Msimbazi are said to have agreed to sell Okwi to Amakhosi according to Ugandan publication, Kawowo.
"The Uganda Cranes international who plies his trade with Tanzania giants Simba SC has reliably agreed personal terms with the South African side."
"Reliable sources also indicate both clubs have agreed on the transfer of the player who has been instrumental in helping the Msimbazi reach the group stages of the Caf Champions League," the publication reported.
Okwi was heavily linked with a possible move to Chiefs' rivals Orlando Pirates in 2012, but the deal never materialized.
If his move to Amakhosi materialises, Okwi will join his countryman Godfrey Walusimbi at the Naturena-based side with the two players having previously played together at Ugandan club SC Villa.
Walusimbi joined Amakhosi from Kenyan Premier League champions Gor Mahia at the beginning of the current campaign.