Does the person inherit through a will or under statute? For both the technical answer is the property transfer upon the death and can be conveyed immediately. The practical answer is different.
If there is a will, and the will is unlikely to be disputed, you can do it as soon as the judge appoints an executor, which can happen in a very few days from the date of death. I've seen some real estate transfer within 72 hours of the death, but this was a transaction that was already in the process and the title was supposed to be signed over when the decedent went into the hospital, where he lingered for only a day or two. So everything was in place and the daughter, who was the sole beneficiary under the will, was fine with going forward. (The transfer involved both real estate and her father's business.)
Without a will it's going to take longer to sort things out, but if there's a reason, could be done within a couple of weeks.
But normally, as Snick says, I'd be looking at the six month mark. And depending upon the state, there may not be an actual conveyance, beyond the probate estate. A will is actually a conveyance document.
Best of luck,
Jim Clark-Dawe