The 28-year-old player has been training with the reigning Premier Soccer League (PSL) champions since July 2019 as he looks to earn himself a deal with the club.
Mosimane has already revealed they are looking to reinforce their striking department with another quality striker having signed Uruguayan hitman Mauricio Affonso two months ago.
“We have [Mauricio] Affonso and [Sammy] Seabi – and we will probably look at Tokelo, maybe we might give him a chance. You never know,” Mosimane told the media.
Rantie is currently a free agent having parted ways with Cape Town City midway through last season.
The Citizens cited personal problems as a reason for the former South Africa international's exit without making an official appearance for the team.
“We will talk to him and find out how he is feeling, how does he see it. I mean this guy was playing in the Premier League and in Turkey – there must be something there," he continued.
"Let’s give it a try, give him a chance to play and let’s give a South African player a chance to play. We’ve got nothing to lose."
With Rantie being a free agent, the Brazilians can complete the signing of the former AFC Bournemouth forward even after the current transfer window closes on Monday night.
"It’s always good for us. I have never seen a problem since he has been with us, that is why we are considering him,” the former Bafana Bafana coach concluded.
Sundowns have signed Affonso, Seabi and Nyiko Mobbie during the current transfer window.
However, former Free State Stars defender Mobbie has since been loaned out to Stellenbosch FC.