Dear Jagadish,
This is srikanth here. As you are still in the studying phase i suggest you to wait till another 3-4 Years to do your SAP (in Module of your choice). This suggestion is basically for the below reasons:
1. You need to have atleast 2-3 Full time Post Qualification Exp. in HR (It could be any verticle in HR).
2. You would be required to know the know how of dealing a particular aspect in HR Functions be it Recruiting or Training or PM. So you need to be perfect in your basics and need to know the process how the things are done.
If still you want to go on with SAP in HR or any other module my suggestion is: IT majors like Satyam, Wipro take freshers train them on these ERP systems and take them as trainees and retain them for 2-3 years you could check out for such openings...
Regards,
Srikanth