My husband who was on visit visa went for the medical with his original passport, visa copy, photo, passport copy of both mine and my husband.(This needs to show only if they ask). Once the medical will get completed,(if you have registered your mobile number in metrash, you will get an sms from them that your husband's report will be fine or not), after two to three days you can go directly to the immigration for the extension of the visa. No need to take the report by yourself. There they will ask you for how many months needed to extend the visa. Its upto you whether to extend completely for five months or per month. If it is completly, then pay 1000QR by card or 200QR per month. They will stamp the visa in the passport. Thats all my husband have done for his visa extension.

Hope the information above is helpful to you