If I am on a deed to property but not on the mortgage, if the co-owner who had the mortgage filed bankruptcy, what are my rights?

If you are on the deed you are an owner of the property.  There are a number of ways you can hold title to the property.  Do you know what your percentage of ownership is?  Were you present when the closing on the property took place, if so did you sign naything for the mortgae company?  If the property is sold or foreclosed on you are entitled whatever your percentage of ownership after all liens, taxes and bills for the sale are paid off.  So if the house sells or is foreclosed on and there is $10,000.00 profit from that transaction and you owned 50% of the property then you would be entitled to $5,000.00.  In the end you are entitled to your share of the property.  It can get a bit more complicated depending on how you hod title to the property.