Cancellation of release deed case filed by my brother

After the death of my mother the family property was transferred on my name by released deed duly signed by my younger two brothers and father. My one brother took undue advantage of illness of my father and made a will mentioning cancellation of the said release deed. ( The property was originally on my mothers name and not owned by my father) He has filed a case in Mumbai city civil court Churchgate for the cancellation of the said release deed on some false reasons. The property is in Andheri , but he has filed a case in city civil court at Churchgate. ( He stays at worli) First he filed a case to Bombay high court but court directed to file the same in city civil court. (as the property value is not much) 1 : Can the registered release deed be canceled ? and how I can secure my rights and property? 2 As the property is in Andheri, then how he can file a case in Churchgate city civil court ? as the jurisdiction should be Goregaon Dindoshi court? 3 Can I raise this point in City civil court Churchgate and ask to transfer it into City civil court at Dindoshi? 4 Can any one file a property case in any court ? or it should be in the court which comes under the jurisdiction?