1. You should file a declaratory suit praying for declaration that your ancesters owned the said property and you are the present legal heir of the said property,
2. In the said suit also pray for an order upon the registrar for cancellation of the registration of the said property with the said fake documents,
3. While filing the said suit, you should submit documents evidencing the ownership of the property by your ancester,
4. The Court fee will be the highest prescribed in your state in your case.