It depends on the nature of appointment. If the appointment order specifies that the employment is for a fixed period of 4 years or 4 years and 6 months or till 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, whatever be the nature of employment, he would have got gratuity. Though there are a few court verdicts which had interpreted working of 240 days in the fifth year as one year service, the same cannot be applied in your case also because six months period is not sufficient to make it 240 days in the fifth year.