It may end up going to auction where you'll have to pay cash at your county courthouse
I just went through that with a property for my buyer, although the owner isn't in jail I do not think. When the time frame for the seller to redeem that property has expired, the bank can then take control of the property and sell it. You need to contact the lender and speak to their department handling the foreclosure. You can get a lot of the info you need from the registry of deeds wher the proprertyy is located. You can get a copy of the deed and mortage which will give you what you need to find the bank and contact them. They will be glad to hear from you as banks do not like being property owners. If you need hekp with this, let me know and I will have an agent from our local Keller Williams office help you get it done.
You need their loan number(s), SS# DOB etc. The bank will also require that you work with a Real Estate Agent. They will NOT deal with you directly.