Gauteng education MEC Panyaza Lesufi said around 69 schools may not re-open on Monday because construction was halted during level 4 and 5 of the lockdown.
But lesufi said most of the schools in the province will be ready on 8 June to receive grade 7 and 12 learners.
Last Sunday Education Minister Angie Motshekga rescinded her decision to open schools, saying that some schools in the country had not been sanitized, did not have personal protective equipment and were thus not ready to re-open.
Under level 4 and 5 of the lockdown, construction was stopped as it did not qualify as an essential service.
Lesufi said that has delayed the completion of renovations at many government schools in the province.
He said some schools could not start learning on Monday because they did not have parameter fences.
The education MEC said alternative arrangements were being made for pupils who could not use their schools to be taught at venues like local churches and halls.