Karachi is 2 hours ahead of Doha
Best overlap: 8:00 AM to 4:00 PM in Doha is 10:00 AM to 6:00 PM in Karachi.
Plan around 8:00 AM to 4:00 PM in Doha, which is 10:00 AM to 6:00 PM in Karachi, to catch everyone during office hours. That's a roomy 8 hours of common time each day, so finding a slot that suits everyone is rarely a problem.