If I applied for visa stamp in canada, VO approved my case but put it on security check can I still allowed to come back to USA only with valid I-94?
-- I am not sure about this security checks for pakistani citizens. But here is my guess based on some common sense:
Since the visa approval in the case you mentioned will be based on the results of security check, you will not be able to use the AVR. (because the visa is not given yet and the final decision is contingent upon the security check).
If I go to canada with PR of canada and from canada I go to my home country pakistan then came back to canada and then enter to USA from canadian border still I need multiple entry H1 visa ?
-- Yes, you will need a H1 stamp (visa) and you will not be able to use the AVR because you left Canada (which shares the land border with the US - important to use the AVR) for Pakistan.
-- I am not sure about this security checks for pakistani citizens. But here is my guess based on some common sense:
Since the visa approval in the case you mentioned will be based on the results of security check, you will not be able to use the AVR. (because the visa is not given yet and the final decision is contingent upon the security check).
If I go to canada with PR of canada and from canada I go to my home country pakistan then came back to canada and then enter to USA from canadian border still I need multiple entry H1 visa ?
-- Yes, you will need a H1 stamp (visa) and you will not be able to use the AVR because you left Canada (which shares the land border with the US - important to use the AVR) for Pakistan.