Interim Injunction restraining Alianation

Dear Sir/Madam High court has passed a Interim injunction restraining the respondant from alianating the Suit property untill the disposal of main suit. The respondant is Title owner of the property with All relavant documents and got the property via a settlement deed from his father Mr X (only daughter). This property is not an ancestral property and was a joint family property which was partitioned by Court and settled on Mr X name and he has been an absolute owner of the property for several years...later he made a settlement of the property to his daugter via a gift deed. now some third party Mr.Y who claims that he is the son of the first wife of Mr X (shows up after 30 years) and he executed a sale deed to some local goondas claiming he has got rights on the property (welcome to TN registration dept) the registrar took bribe and executed the sale deed with out checking the title ownership, Encumberance cert, Patta, parent document etc. On top of this, Mr Y filed a Suit in district court claiming that he has share on the property. now when the Respondant Mr X daughter is trying to Sell the property, Mr Y has approached the High court and got a Interim Injuction (by Ex partee) restraining respondant from alianating the suit property. They are not sure of a Private notice was served to them. but the order was passed as Ex partee Question: 1. Can this Stay order be vacated by challenging it. as the respondant have all relavant and legal documents to proove her ownership. 2. Is there a Prima facie in this case to issue an Injuction? 3. If challenged, will the high court look in to the merits and vacate the injunction or just dispose teh challenge by saying let the lower court decide the main suit. 4. Can the respondant build a house in the suit property atleast if not able to sell off Please help.