Lands you control can tap to produce at least ({5} magic symbol) ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) .
({1} magic symbol) plus enough mana to pay for commander tax, if applicable available.
Steps
Activate all mana-producing lands you control by tapping them, adding at least ({5} 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) plus commander tax, if applicable.
When Zacama enters the battlefield, it triggers twice.
Resolve the first trigger, untapping all lands you control.
Activate all mana-producing lands you control by tapping them, adding at least ({5} magic symbol) ({R} magic symbol) ({G} magic symbol) ({W} magic symbol) .
Resolve the second Zacama trigger, untapping all lands you control.