Bro, only way to Tuas is either taxi or bus. My advice (since it is an interview, dont want to be late for that for sure) is to get a taxi app when you arrive at SG like GrabTaxi, SMRT taxi. GrabTaxi is better app. SMRT taxi driver really hate going to Tuas.

It is very hard to get taxi to go there because it is a lost for them to go in due to bad traffic condition. They are currently building multiple highways there that makes it worst compared to last time.

My advice is to always travel at off peak time (between 7-9am and 4-7pm). Also avoid Fridays, as most taxi drivers go pick up hot chicks at the city instead of dirty filthy whore shipyard worker like us.

Always plan your trip 1-2 hours ahead, make your taxi booking at that time. Also get a confirmation from the driver and operator. Once I told the taxi drive Sembawang shipyard, he drove me to Shipyard road. I was with my colleague and both of us said the same thing.

Get a local sim is very cheap. Then get an application called GrabTaxi.

http://grabtaxi.com/singapore/

They allow pick up points and drop off as well.

Hi, I presume you are from Johor City since you mentioned JB. If so, you can take either the yellow bus (CW bus) from there to SG, and alight at Kranji MRT. Alternatively, you can take bus 170 (SG bus). Ask around if you ain't sure at the custom there.

From Kranji MRT, you can take the train to Jurong East, then transit to Joon Koon Station and alight (you will need an ezlink card for this, can be bought at the counter or nearby 7/11). Take cabs to the destination from Joon Koon station. 

However, if you are coming to SG from Nusajaya/ Bukit Indah or somewhere near to 2nd link, you can take the CW bus from Giant at bukit indah (CW 3 to Jurong East or CW 6 to Boon Lay). From Giant, just hop to any of the CW buses to SG, as u can switch the bus to either CW 3 or CW 6 after u pass the SG immigration. I will advise you to take the CW 6 bus from there, and alight at Boon Lay then take cab from Boon Lay to your destination.

Hope the above helps.