A patent can be registered internationally by following a PCT route or by convention route/direct filing. The PCT route helps an applicant to file patent application for the same invention in many countries simultaneously. Provided, the designated countries are member of the Paris convention. The PCT international application can be filed with the International Bureau under WIPO as the receiving office or can be filed with the Indian patent office as a receiving office. Requisite fee along with application should be submitted. An international filing date is accorded to an applicant by the receiving office having the same effect as having being filed in designated countries chosen by an applicant. The patent application is filed in triplicate with the Indian Patent Office. The first being the “record copy” which is sent to International Bureau, the second being the “search copy” which is sent to the International Searching Authority. The third being the “home copy” which is kept by the receiving office. As per section 39 of the Indian Patent Act, 1970, prior permission from the Indian government has to be taken by a resident of India, to file an international application under PCT or the same application has to be filed in India, at least six weeks before filing of the international application. The provision of this section is there to check, if any information related to the defense purposes is being leaked to other countries.