Hi guys I want to ask if I were to purchase an ipad air/mini with wifi+cellular from Australia, can I use it with digi/maxis/celcom back in malaysia?

Thanks in advance.

If you buy from Apple Store, it is unlocked and you can use it in Malaysia. But after conversion, why would you want to buy it there? Even after 10% GST deduction?

AUD 598 vs RM1,599 for 16GB iPad Mini. After GST, it is still about AUD550 (it's not exactly 10%). Using a conversion of AUD1-RM3, it is RM1,650.

I normally buy from Perth if I am there when a new product is available in Aust but not in Malaysia.

Unless you are getting a plan for yourself there then bring it back for someone in Malaysia to use. You have to check whether the Telco you buy from sells you the locked or unlocked version.