I know you can register at Jalan Semarak, but that's somewhere in KL. If you're somewhere in Puchong, why not try Putrajaya? Takkan there's no JPN there. Or if there aren't any there, the Kementerian can probably help you locate the nearest place where you can enter/register.

Or, maybe you can contact any universities near you. And register for MUET under them. The result will be mailed to you anyways, so there won't be much problem of having to go and pick up the result etc.

And if I'm not mistaken, you can register for IPTA even if you haven't sat for MUET. You'll have to sign some pengisytiharan or something saying you'll sit for MUET during your studies. If you do this, then you can register for MUET under your current IPTA. Lagi senang.