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.
20th October 2016 From India, Bangalore
As rightly said by Mr. Divekar, when applying for the opportunity, you must have gone through the job description.
Also, your superior must have briefed you at the time of interview as well as at the time of joining the responsibilities and the activities you are expected to carry out in the organisation.
Incase if you are still not clear about your job responsibilities, I suggest you please go through the job description. If you do not have the JD, please get it formulated from your superior. This will help you to get a clarity on what activities you have to perform.
21st October 2016 From India, Mumbai