Round up whatever documentation, referral letter, medical reports you have. In theory, any klinik with a doctor with a stethoscope who's adept at listening heart sounds can start to know whether your VSD is noticeable.

But since an echocardiogram is the standard in imaging and assessment, you'll need that done by anyplace that has a cardiology facility. I'm going to assume your VSD is asymptomatic growing up now, so the most convenient would be to go for a private hospital to avail a cardio consult for an echo. Public hospital would put you as a low priority if asymptomatic ever since.