VISA INFORMATION

I have been selected by the Higher Education Commission of Pakistan for Post Doctorate . I have an acceptance letter from the same professor. Now the HEC wants to submit all documents including VISA before 30th April , 2020. I just want information regarding visa requirements for Post-doctorate study and also for my family visa including my wife and two kids. I also want to know about the process as well as timing of embassy to visit especially in theses days.