Visa tourist - On which visa can i come to Singapore to seek work?

You are allowed to apply for jobs and attend interviews during your stay in Singapore with a standard tourist visa (SVP). After you signed an employment contract, the company will apply for your work pass (EP or similar).

I just read your profile: It says you have a Diploma in Mechanical Design.
Are you aware that, in Singapore, a Diploma is not a university degree but merely a technical certificate? With such, you will have problems finding a job and can earn only up to S$4000/month or so on an S-Pass (i.e. too little to have your own apartment!).
If you actually have a degree (which confusingly is called diploma in some European countries), you should change the wording on your CV.

Hi Beppi,

Thanks for your useful information. I know that the MOM consider before to give the Employment Pass or similar the years of work experience and the qualifications, so in my case I have strong and long experience, around 15years on Mechanical Design, and Diploma from high school. Of course it will be not easy but not impossible...

High school leaving certs are not recognised as diploma in Singapore, only as A-levels.
And work experience can never replace a degree in the eyes of MoM. (Sorry, but that's their rule!)
Without a university degree, you only have the chance of an S-Pass (low salary, as I mentioned above) or an EP if you earn a lot (the threshold used to be S$8000/month, but will gradually go up to S$12000/month).
But of course that applies only if the employer can convince MoM that there are no locals who can do the job and thus they have to hire you. I think that quite unlikely, especially in mechanical engineering, where there are plenty of local fresh graduates (who need to be hired before you)!

Hi beppi and everyone .my friend came here in SVP on Oct 9 .it expire on Nov 8 .he want extension. So v applied for extension using e-xtend webpage on Nov 3rd. .in that v wrongly typed the travel document number . so the extension was rejected .v try to re-apply .but it was failure .wat can v do now .please reply soon. I m waiting

If the extension of SVP is rejected, he probably must leave the country for a week or so.
Alternatively, call ICA and ask for advice.