I'm from Hyderabad, India. I want to go on a visit visa to Singapore to look for a job. If I get a 30-day visa, how many days can I stay in Singapore? Is there any way to extend the visa?
No, you are not supposed to job search while in Singapore as a tourist, where one is a Visitor on Short Visit for Social Purposes. The government of Singapore views social purposes as visiting families, friends, relatives and for tourism. Contacting potential employers, visiting businesses, going on interviews are not considered tourist activities.
Usually granted for 30-day stays, you are able to apply for an extension of stay, which cannot total more than 89 days from the date of entry). Overstays and violations of Singapore's visa conditions can have serious repercussions and, as your goal is to live and work there, the risk may not be worth it.
Even if you were fortunate enough to have an employer interested in you while there, you would be asked whether you have a work visa. Without that, you would be a less attractive candidate, as you would have to leave the country while the company applied for one for you (if, indeed, it would even be willing to do so). With Singapore a highly-desirable place to live and work, it's a very competitive market.
A better plan might be to apply for positions while in your home country. Singapore's Ministry of Manpower has number tools to assist you in both the job search and relocation.
And, should a company be interested in hiring you, you can enter on a Social Visit Pass to attend a pre-arranged job interview or contract negotiation. The potential employer would supply you with the requisite Letter of Introduction for Visa Application (Form V39A). In that instance, should the company then offer you a position, you would not have to leave while it secures permission for you to work, as long as the process happens within the valid time period of your pass (and any extension, if needed).