I had hamsters too, when I was a space between the insulation and the wall, and he was gone for 3 days before he finally turned up. It depends on whether your hamster escaped somewhere in the house or outside. If it is outside, You'll probably never see it again. And 6 days is a very, very long time for a creature as small as a hamster to go without food or water. I'm sorry. Please don't get your hopes up that your hamster is still alive.
        Vickie

If it's there. On the other hand, if there is a tiny hole or area through which the little creature could squeeze out of the house, you must be prepared for that to happen. Our hamster, fortunately, got stuck in the walls and had to come out the same way he came in.
I hope your hamster comes back. You might try leaving hamster tibits around various areas of the house, to see if you can track him. For that matter, you could always use a humane trap, like they do for mice and other creatures, it lures them in with food and then shuts the gate behind them so they cannot get out. It is absolutely painless and will not harm the animal.
At my job, we had to use one of these traps to capture a feral cat one time, in the winter, who was lurking and pooping in our warehouse, we were afraid for its safety. The trap worked beautifully, and the cat was taken and released to a farm where she could at least be a barn cat.
Good luck!
     Vickie