Because you didnt mention whuch subject in post graduation, I will give general information. There is no such entrance exam for studying post graduation courses in foreign countries. There is only TOEFL/IELTS. They are language proficiency tests to check your adaptability in English speaking countries. And then there is GRE Subject test which is specifically designed for various subjects. So the universities know your competency in the subject you are applying for. Apart from that, there are no PGETs.