Lands you control can tap to produce at least ({3} magic symbol) ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) .
({3} magic symbol) plus enough mana to pay for commnader tax, if applicable available.
Steps
Activate all mana-producing lands you control can tapping them, adding at least ({3} magic symbol) ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) .
Cast Zacama either from your hand or from the command zone by paying ({6} magic symbol) ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) and commander tax, if applicable.
Zacama enters the battlefield, triggering its ability twice.
Resolve the first Zacama trigger, untapping all lands you control.
Activate all mana-producing lands you control can tapping them, adding at least ({3} magic symbol) ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) .
Resolve the second Zacama trigger, untapping all lands you control.