Mr.Engineer said:
how they verify educational documents? by sending directly to institutes?
Many countries like US, UK Canada etc have bilateral/multilateral agreements with Govt. of Pak regarding info sharing on immigration and border controls. These agreements entitle a foreign mission/embassy to have restricted/viewable access to number of our records/databases.
E.g. In case of Pakistan.... US, Canadian and all European embassies have access to search and view NADRA’s main database of registration, passport and immigration control. Similarly they also have an agreement with HEC for Reg. and degree award verification records.
That facilitates them a lot while they are sitting in Islamabad embassy in or anywhere in the world. Plus in case of CHC Islamabad, they have a special desk for LND office which facilitates and answer all LVO queries where physical verification is required within Pakistan.
I know these things coz in beginning of my career I worked as a consultant for legal rights and information control in public sector for three years.
Hope it helps in getting some idea of this complicated process.