How to deal with discrimination in recruitment by authorities

Dear sir this is amruth i have appointed in SAIL as Jr operator cum technician trainee on the basis of ITI qualification for the least grade S1 in dec 2006 but at the same time or after my appointment in other plant of SAIL the same qualification candidates have recruited as same designation in S3 grade i came to know this discrimination few days back i asked management regarding discrimination made in my appointment but the management says not its as per recruitment policy but in the recruitment policy says skilled personnel should recruited in S3 Grade but am confused that what is the skilled qualification,semiskilled qualification and in which category the ITI qualification falls and the which authority says its skilled or semiskilled. so please clear my doubt thanking u amruth