Unfortunately, there is not a clear cut answer to this. It really depends on the lender. Some are on top of their game and get things moving and the property will be back on the market within a couple of weeks. Of course, it does depend on the condition of the property. If the property was trashed and needing repairs they usually like to get them cleaned out first. And sadly, some lenders let properties sit for a couple of months before they get started.
If you know the lender you may get on the phone and do some investigating. I have gotten to the right person at the lender before they were able to actually list it. I wish you luck with this. My husband and I bought a foreclosure in May and we got one of the lenders that drug their feet at every step. It can be frustrating but well worth it in the end.