Usually in Doha (Industrial Area Centre) its open from morning 7 to evening 6. I have not been to the Wakrah centre and i am not sure about the timing.

Once you get a approval of fitness, you can take the form along with the isthimara to the police station at the testing centre or to the Mamoora police station Nr the wholesale makket and pay a fee of Qr. 100 and renew it.

If your car is less than 3 yrs old u dont need to do a fitness test, you can take it directly to the police station and renew it.