then start with laxmikanth after finishing studying basic books.
supplement this with nicholas henry, stephen robbins( org behaviour) and arora goel(indian administration)
do current part like recomm of committees and any commissions that have been constituted.
meanwhile, buy a good test series or question paper set and solve unitwise questions and then full syllabus papers later on.
You are all set to get abt 85-90 in pub ad after negative marking.