Legal Question in Criminal Law in California

It's impossible to tell without knowing the offense that sent him to prison. For most crimes, the defendant becomes eligible for parole after serving half the sentence; for offenses classified as violent felonies, the defendant must serve 85 percent.

You say he had about 9 1/2 months of credit against a sixteen month sentence, which gives him a little more than six months to serve. Good behavior credits will be deducted from that. His prison counselor can give him a more accurate calculation of his projected parole date.