Differ from University to University. University like NTU, NUS require 2 years work experience & GMAT mandatory with 1st class degree. Entry requirements for undergraduates are 85% above. SAT is require for NTU & SMU. NUS doesn't require SAT. Private sector: undergraduate require. Postgraduate: first class degree is require.
University intakes August + July. Once a year. Polytechnic have July intakes running throughout the year.
1st week of January is deadlines for polytechnics. 28th February is the university deadlines for M.B.A. and MSc. course in university deadline is March 31st December is the deadline for Undergraduate courses in NTU. For private institutes you have to apply 3 months in advance before the intake.