Yes, the police do keep a criminal register but, no, only
certain employers (civil service, aviation, maritime, security) can
ask them to help screen job applicants. Actually, I don't think a
regular MNC have the power to do this, having heard of cases where
overseas postings collapsed because the foreign country discovered
so-&-so's background & then refused him entry!
As far as I know, only those with really serious military
convictions will be recorded on the register. Not so much the
length of the sentence, but in relation to the offenses committed
under the Penal Code. You can google for the info yourself but,
offhand, they pertain more to deeds like desertion,
insubordination, assaulting a superior, mutiny, etc.
Hope this helps.