it would largely depend on your budget, how much money you are willing to spent. different university have different registration costs and the place you want to study in, for example UK will be more expensive that USA, but in USA you will need a GRE that will take around 6 to 12 months of extra study and fees. I studied at Jacobs University Bremen in Germany and it was a really nice experience. I have recommended one friend, he went and he loved it. check their website https://www.jacobs-university.de/. Good luck.