It's a slang term
commonly used in Bruneian-Malay
which means "Don't be a retard" or "Don't be a dumbass", a shortened version for "Jangan jadi paloi"
In
Standard Malay, it means "Jangan jadi bodoh sangat".
Guy 1: Inda ku sabar aga ke NYC, liat
Eiffel Tower (I can't wait to go to NYC, visit the
Eiffel Tower)
Guy 2: Jan Paloi,
Eiffel Tower tu di Paris (Don't be a retard, The Eiffel Tower is in Paris)