HR is vast subject it is not possible for anyone to tell you that what questions an interviewer can ask.
But I will try to guide you,
1. study your resume carefully first, many candidates write objectives in the resume but when interviewer ask about what is objective then most of candidates fails to tell it. so study your resume first.
2. You must know what functions HR department carry in any organization.
3. Study basic laws applicable to any factory/company,
you should know What is Lockout, Closure, Layoff, Strike, Retrenchment, Definition of accident, Welfare facilities, safety, Leave rules, etc.
5. Study all compliance made by HR, Factory license renewal, PF return, PT returns, welfare fund return, Employment exchange return etc.
these are the basics, you need to grab all areas of HR
16th July 2014 From India, Hyderabad