After emigrating, I immigrated back.

If you work illegally for eight years, you will be fined S $5,000-S $20,000, or imprisoned for two weeks to six months, depending on what the customs department and the police department decide. If you are a man, you will be whipped if the circumstances are serious, but it is definitely impossible to go back to Singapore. You won't be granted any permits, including tourist visas, for at least six years, but not after six years, because Singapore's criminal record will disappear every six years. Only foreigners are allowed.