Mexico City is 9.5 hours behind Tehran
Best overlap: 5:30 PM to 6:30 PM in Tehran is 8:00 AM to 9:00 AM in Mexico City.
Target 5:30 PM to 6:30 PM in Tehran, which lands at 8:00 AM to 9:00 AM for the Mexico City side. Mexico City is 9.5 hours behind Tehran, so common hours are scarce (about 1 hour). Lock the slot, keep it short, and follow up in writing.