Do the translation yourself, attach together with the document being translated and have it certified true by someone reputable i.e. school HM, ketua kampung etc.

But if we're talking about transcripts from uni (i.e. diploma, degree etc) the uni would have to do the translation and send it to NUS direct in a sealed envelope with the uni's stamp.

I translated all my certificates myself when applying for one of the schools in the US, and it turned out fine (I assume it is because I'm admitted ). you don't have to translate it word by word, as long as they know what the certificate is all about then it's going to be fine. just make sure you have someone to certify the translation for you (as in get it stamped). pegawai daerah, pengetua and etc will do.

What certs are we talking about here? If it's the uni transcript NUS would have given you a transcript request form to hand over to your uni and they will translate + seal + send to NUS for a fee.

Otherwise just translate like such: "Sarjana Muda Kejuruteraan Mekanik dengan Kepujian" to "Bachelor in Mechanical Engineering with Honours" etc. Not really difficult.