Typically our landlords are only willing to hold a vacant property for about 2 weeks on an approved applicant. That being said, sometimes a landlord knows well in advance (a month or two out) that the current tenants don't plan to stay and will list the property ahead of time. While it may be more of a hassle to show these properties, it sometimes can save you some time and money competing with those people that want a place right now.
On to your comments about Round Rock being great, it is. But it is surrounded by great cities as well and it can be hard to tell in places whether you are in Round Rock or Austin or Cedar Park or Pflugerville because they all kind of run together. Follow the higher rated schools to find the higher rated neighborhoods.
Hope this helps. Start your search here and if you like it, give me a call when you want to look at some places. http://www.sellanaustinhome.idxco.com/idx/16847/basicSearch.
It really depends as each landlord is an individual owner and can do whatever they want. Because the market is pretty hot right now it is doubtful that that a landlord would hold a property over for more than a couple weeks but again you never know. You are also getting close so there will most likely be some properties that will be hitting the MLS that will be available towards the end of May or beginning of June.
I would spend some time getting to know the different areas and get a feel for the market. From there you can work with an agent who can do some searching for homes that have availability move in dates closer to your needs.
If you need a good lease agent please let me know as I would be happy to refer you to a great one who knows Round Rock and the surrounding areas very well.
Hope this helps.
REALTOR® & Mortgage Broker
Austin Real Estate Pros | 360 Lending Group
office: 512.669.5599 mobile: 512.633.4157 http://www.AustinListed.com | http://www.360LendingGroup.com