In the game Portal, yes.
In real life... there could be something called a portal gun. But there's no known way of making something that works even approximately like the gun in Portal.
search Portal gun DIY indymogul on you tube for instructions on how to MAKE your own portal gun
you can play mario bros with portal gun online
No
The only gun there is on portal 2 is the portal gun which creates the portals. You shoot a portal on white surface, and shoot another portal on a white surface, and you can move yourself and objects through these portals.
No. Such a thing is not possible in real life. Even if wormholes exist, they would not work the way they do in the game.
yes
no
No
Well, unfortunately it is impossible to make a portal gun without the mod. Sorry.
No
They don't make it(yet).
Try google