Sale of property

Yes it can be done in court of law in only one condition i.e. ex- coowner prooves in court of law that relinquishment deed was not done out of free consent( fraud, coercion, duress, misrepresentation or undue influence) . You should seek a legal advisor. Contact us at https://www.wazzeer.com  with a detailed analysis of your problem so we can help you out.

Since the other coowner has also relinquished his interst in coownership of property  in favor of  other copwner it can be sold by the other coowner provided there is no coercion, undueinfluince and fraud.Then only it can be a valid sale.