Can they make us take the garage down?

What is the name of your state?I am in Indiana and my Bf and I just bought a house. The home was a foreclosure to start with. The house sits on 3 lots, which we just recently found out in the last week the house was sold to us as 2 lots. The lady who died and origanally owned it owned all three but only had a mortgage on two of them the other was paid for free and clear. The two that were sold to us are totalling 76w X 120 the 3rd parcel is 40 X 120. The garage which is attatched to the house is on the thrid parcel which we have just found out that is going up for auction Oct 3rd. When we bought this house we were told all three lots were in the purchase , which we didnt know there was three lots we thought the whole thing was in two lots, but they blew us by the legal paperwork so fast we didnt notice the thrid was not in the agreement and we unfortunately didnt get a survey. We are both new to this and this is our first home. My question is this... Can they make us take the garage down which again is attatched to the home and has been since 1969 or is this grandfathered? Please help us? We dont know where to turn this house which we thought was going to be our home has become our nightmare. Thanks a bunch.

1 lot 2 lots or 3 lots which is it?............your zoning laws rule.?

There is a total of three lots. We didnt know that at the time of sale. They showed us the house which sits on a block by itself. The Realitor told us the property was included. We found out last week that it was sold to us as Two lots and the third lot was up for tax sale in Oct. The garage sits partially on the third lot. But has been since the house was built. We want to know if they can make us take the garage down?