The number of entries is depending on which type of Rwanda e-visa that South Africa citizens apply for. The answer for this question is yes but only for East Africa e-visa. With other types of Rwanda e-visa, South Africa nationals can not enter Rwanda more than once. If your e-visa expires, travelers must apply for a new one to have permission to enter Rwanda. E-visa restricts the number of entries but travelers can apply for an e-visa many times. So make sure your e-visa is still valid or you will be fined by the Rwanda government.
Typically, there are 4 types of Rwanda e-visa that South Africa can use for tourism, short-term business and transit:
Tourist e-visa: Allow travelers to enter the country one time only and stay in Rwanda within 30 days from the intended date of arrival.
Conference e-visa: Allow South Africa nationals single entry and the duration of the stay is 30 days in total.
Transit e-visa: Permit single entry for South Africa citizens and they can stay in Rwanda for a maximum of 3 days overall.
East Africa e-visa: This is the only type of e-visa that allows travelers to enter Rwanda as many times as you want between Rwanda, Kenya, Uganda for 90 days from the date of arrival.