Dispute involving multiple parties

The facts laid out by you point towards an illegal transfer of property. In such a case, you can either file for a declaratory suit to get your title declared, or file a suit restraining the other person from carrying on with the sale. In any case, the person who carried out the sale was not competent to transfer the property and hence any transfer made by him to any other person is void in itself. As per your question regarding making the third party a party to the suit, I should tell you that you will not require to do so, provided that the third party bought the property in good faith, believing the false owner to be the true owner. But if the third party knew about the fact and still purchased the property, he can be made a party to the suit. The thing is that the transaction between the wrong buyer and the third party would be void ab initio, as the wrong buyer was not competent to transfer the property.