It depends on the nature of the appointment. If the appointment order specifies that the employment is for a fixed period of 4 years or 4 years and 6 months or until the completion of the project, then the question of retrenchment compensation will not arise. At the same time, if the employee had worked for 5 years, regardless of the nature of employment, he would have been entitled to gratuity. Though there are a few court verdicts that have interpreted working for 240 days in the fifth year as one year of service, this cannot be applied in your case because a six-month period is not sufficient to reach 240 days in the fifth year.