Service matter related.

Sir(s)/Madam(s), My friend is working in Central Government Department on the post of Multi-Tasking Staff (MTS) since 16.12.1988. He was directly appointment by his Office through Direct Recruitment method and accordingly, he has been kept in Seniority lists of MTSs of his Office upto 2004. In 2007 and on other occasions he has been kept in Sr. Lists of MTSs (Central Staff) who were recruited through SSC issued by Ministry and removed from Deptt's Sr List of MTSs without his consent. During that time some MTSs from this Sr. list of Office were promoted to higher posts who were junior to him in that lists and he was not considered due to non-inclusion in this list. Surprisingly, in 2011 his Office kept him back in Deptt's Sr List of MTSs and again in 2013 and later in the Central Lists of MTSs. He was threatened on many occasions against to represent these discrepancies. Now, he wants to get his Sr. Back in Deptt's Sr List of MTSs from retrospective date. Since, his Office has given him final reply that his name cannot be included in Deptt's Sr List of MTSs because he had never represented against these discrepancies of Sr. Lists during 2007. Can anyone help and guide him in this regard ? Can he challenge Seniority lists now, if so please quote the DOPT Rules/guidelines in this context ? and oblige please.