Normally exchange programme means that you are still a Malaysian student, with your details and tuition fees payable to the university at Malaysia.
Therefore, PTPTN still continues with the exchange programme. The contract still continues.

If you go for transfer a.k.a twinning, you will transfer your details to the foreign specified university, with your tuition payable to that foreign university.
Technically, the PTPTN contract will be broken once you go for transfer programme.
The loan will be forced to stop, and you need to pay the debt back.
Also, PTPTN exemption cannot be applied for this case.
When to start paying... that's out of my knowledge.

This post has been edited by ZRong223: Sep 5 2016, 03:35 PM