Dear Devranian Kumar
The hieraachy is depanded on the type of institution i.e. if it is a national institute, central institute, University, College etc. normaly the desiganation of the posts in the library are as per the UGC /Aicte/Medical council's defined nomenculture, like Librarian, Dy. Librarian, Documetation Officer, Curator, Assittant Librararian, Data oprator, Library assitance , Steno Typist , Library attendent, Binder,Library peon. you may refer UGC and AICTE Hand book for their work and responsibilties