Dear Swapna,
Give more details about the size of the company, the nature of its work, and your background. Also, kindly tell us in which mode you are doing your MBA?
Let me tell you what you face is nothing new. When my friend joined a multinational company as Measurement Engineer, he had nothing to do for 2 weeks; he was asked to study company documents and get familiarised with the organisation and its culture. Another friend was promoted as an Assistant Industrial Engineering Manager and was asked not to do what she used to do as an engineer (Method study, Time study, etc., of operatives work). Then she found that she had nothing to do; it was real frustrating, as she sat in an open office where 13 Bonus Clerks worked non stop, with their supervisor. Later she found out that her boss, the Regional Manager, did not have much to do. To cut the story short, she enrolled on a part-time Master Degree and, eventually, uit the job after years.
So, grit your teeth, study the organisation well and then suggest what needs doing to improve the HR function. If you think that you are a fresher and do not know much about and wanted to learn, I wonder why you took up the job!! Did you do ay research about the company before joining?