how old has a male cat to be before he can get a female preg

 
How old has a male cat to be before he can get a female pregnant?
The male cat is 6 months old. Can he get a female cat pregnant?
answer:
Quite possibly . It has happened that male kittens as young as 5 months have got female cats pregnant! The age varies and you may be able to tell his development by looking at his testicles, but really it's best to just get him neutered now, there's no reason not to do so unless he is a pedigreed cat being shown and is considered such a great example of his breed ( or a good example with a stellar pedigree) that his genes should be passed on to preserve the breed.

If he's not ready yet he will probably be within the next few months ,and it may be accompanied by the whole range of tomcat behaviour including spraying extremely strong smelling urine to mark territory, or running off and getting into fights (and maybe getting bitten and getting a disease from a stray tomcat) . so get the young guy an appointment with the vet!
Yes he can, so it's best that you get him neutered SOON. Call the vet and ask for the next available appointment. Best to get the female cat spayed, too. Neutering/spaying can prevent unwanted kittens (just look at the shelters overflowing), behavior issues such as roaming, and health issues such as cancer.