How many months gaps is necessary for second GAMCA medical test?

3 months gap is required. For example today you complete you gamca medical test, Now you have to wait at least 3 months from today to go for second gamca test. 

Many time it's happens, When you got the job in Dubai and after completing gamca medical test, you got the best offer from saudi. So in this case you will have to go again for gamca medical test for saudi but you are not allowed. Wait 3 months.