Dear friend,
You should have asked this question to your superior to whom you report to.
You work in what department? When did you join your company? When you had joined, before joining, your company might have promulgated Job Description (JD) in the ad for the job. Was this not sufficient? Secondly, at the time of interview, did the interviewer make clear to you about the nature of your job? Going further, before acquiring this the position of Asst Manager, you must have held position of Assistant or Executive. That time did you watch the duties of your superior?
Your query is vague. You may give more information about you, your job and query itself.
Thanks,
Dinesh Divekar