Promotion in central govt job

Sir, I'm an employee of central govt . I was one such employee whose vigilance clearance was sought by my department for considering my promotion. (in August last year). In March this year, department issued promotion order, which did not contain my name. I noticed that many employees in ST category (not senior to me) were given promotion. In this manner, by promoting non-senior ST category employees and not promoting other employees who are senior ,department filled 200 promotion posts up-to December 2018. Kindly reply whether this promotion order is legally correct