Scholarship in Singapore

You should first check if your diploma is recognised in Singapore. You can contact MoE (Ministry of Education) for that.
Then you should check the entry requirements of the school you want to enroll in, to see whether you qualify.
Then ask the school about possibilities to get financial support (scholarships). In my experience it is only available to very good students with an excellent track record - and often not for first year students (meaning you'd have to come for the first year on your own cost - with no guarantee to get a scholarship in the second).
Please note that "diploma" in Singapore means a certificate from a polytechnical school - it is not a university degree and does not automatically entitle you to university entry!