To be eligible for the Post Graduate Diploma degree at NAVAL INSTITUTE OF AERONAUTICAL TECHNOLOGY, Kochi, candidates must meet certain criteria. Firstly, applicants must have completed their Bachelor's degree in a relevant field from a recognized university or institution. Additionally, a minimum aggregate score of 55% is required in the qualifying examination. Candidates should also have a valid GATE score in the relevant discipline. Furthermore, applicants must meet the age criteria set by the institute. It is important to note that these eligibility criteria may vary for different specializations within the Post Graduate Diploma program. Therefore, prospective students are advised to refer to the official website or prospectus for specific eligibility details.