Karnataka Administrative Service (KAS) examination is a three stage process
Stage I. Preliminary Examination (Objective Type) for the Selection of candidates to the main examination
Stage II. Main Examination (Written Examination) for selection of candidates to the personality test.
Stage III. Personality test: For final selection of candidates to various posts/ cadres
You have to focus on the All NCERTs from Class 6 to 12 (Special focus on classes 10, 11 and 12) and make the habit of reading a newspaper, everyday..