Dear Jyothi,
Dinesh Divekar has given you sound advice given the lack of enough information about your organisation and your role in it.
My sincere advice for people seeking general information is to search CiteHR and/or the web. For example I found the following link that gives very brief information on the Role of HR in Six Sigma
The Role of Human Resources (HR) in Six Sigma
You can also gain more information at
Six Sigma Projects in the Human Resources Department
isisixsigma site is a good one for genral knowledge on various related topics.
Methodology | iSixSigma
May I now request you to kindly go through the material and tell us how you think you could apply Six Sigma in your own work. May be once you do that, you may be able to give a presentation to your managers why your company/organisation should adopt it.