HSS won't work because you can't assign a free action to use the portal mid-action. The only thing HSS lets you do mid-action is make that free attack. So you would either have to use the Portal before or after using HSS, but not during.

Multiattack could work, but you'd have to spend one of your Multiattack actions using the Portal. So there really is no advantage to using Multiattack in this way.

what im trying to say is that the guy starts on the portal and, uses a free action to use the portal to the other gateway then he wants to hss can he or does he stop when he hits the other gateway?

I am not sure what you mean by "stop when he hits the other gateway".

If the character is already on Portal 1, you can give him a free action to go to Portal 2.

Now that the free action to use the Portal is done, you may give that character another action. If you want to use HSS with that action, fine. So he uses HSS.

Does that answer your question?

so i can use mutiattack to first open the portal then move then attack? or use mutiattack to first open then move and stop on the other portal?

Multiattack gives you two actions as free actions. You can use one of those actions to activate the portal, but then that leaves you with only one action remaining to do whatever else you meant to do. So Multiattack, on its own, offers no advantage for portal activation.

Instead, your best case scenario is to already be on the portal. Then you use the portal (free action) and reposition the character. Then, AFTER you are done with the portal, you activate Multiattack and do your two actions. Or, if your character isn't already on the portal, use Multiattack and use one of the actions to move on the portal (and the other to attack or place a Barrier or whatever). Then once Multiattack is done, give the character a free action to use the Portal.