Are you saying that your house was foreclosed? Or are you saying that you want to buy a foreclosure? A reverse mortgage is for someone who owns a house free and clear. For example, if you live in a home that doesn't have any mortgage payments and you are owner, then you give your home as collateral to the mortgage company and they send you a monthly check. After several years, you would then have to sell the house for more than is owned on the home.
I hope this explains things a little better. The idea of a reverse mortgage is for senior citizens who spent 30 year paying off their homes and now need money after retirement. They figure, "You can't take it with you" and they will probably die before they exhaust the equity in the home.