Unfair recruitment of executive(technical) in LMRC

Hi! LMRC (a joint venture of govt. of UP and govt. of india ) advertised a vacancy for varios posts in 2018 vide ADVT NO: LMRC/HR / Recruitment /O&M/3/ 2018 dated 21.02.2018. For the post of AM/Civil 07 vacancies were advertised and 07 were finally recruited without giving any consideration/relaxation for the already serving employees in just below grade. Now, LMRC has called for document verification for another 5 candidates on 04/10/2019 from waitlist of exam held in 2018 without any seat being vacant by those who joined in 2018. My question here being is: How can a govt. organization recruit from open market against vacancies which have already been filled and that too after around 1.5 yrs. of declaration of result? i want a stay on this recruitment and i want that the already serving employees must be considered for promotion instead of recruiting from open market. Kindly guide with the legal options that i have in this scenario. U may call me on the given no. if u have any further questions.