PSU has done recruitment on contractual basis for 3 years in AO Cadre in May 2010 by taking written exams followed by Group Discussion and interviewed by executive Director.In appointment letter they mentioned that 2 further terms of 3 years may be granted on basis of performance.But after completing 6 years now the corporation is not in a mood to continue the contractual employment so they gave notice for 30 days about ending of contract term .No increment given to us in these 6 years.PF and Gratuity has been deducted from our salaries.we have completed 6 years of service without any break.What are our chances for regularization??Should we legally challenge the corporation???