Looking for an entry

Your job chances depend on your education, applicable work experience, whether there are Singaporeans who can do the same job (and need to be hired first, by law) and of course on luck as well. Being in the country increases your chances to be invited for an interview, and allows you to build up a personal network - both of which are very important factors!

Thanx Beppi.!! Can you suggest me any good consultancies .??

If you want to work at a consultancy, try the Big Five: Accenture, Deloitte, Ernst & Young, KPMG, PriceWaterhouseCoopers.
In case you are looking for  an employment agent (also often called consultancy by your countrymen): They are of limited usefulness for job seekers in Singapore, and often less than honest. It is better to apply for jobs at potential employers directly.