Hi Madhura,
Though I am not very experienced like the seniors in the forum, have gone through similar situations..so would like to share my little knowledge with you..
As per my knowledge, HR round of interview is basically held for judging the person's personality. Personality includes character, temparament, presence of mind, past experiences, and general compatibility with the organization.
You may ask about his/ her background to know about upbringing, family background, his previous jobs, why he shifted (it gives us a little idea about his nature- whether jobs shifted for better opportunities or just like that, and also about loyalty to an orgn.), his future plans, some questions may be asked to judge his behaviour (such questions are available on the posts in this forum itself!), and based on the feedback of the TECHNICAL experts, your role also may be to negotiate salary, perks,etc.
Don't be afraid..you will do it.
For more info, search on cite HR only. You will get excellent tips for conducting HR round from our seniors, too.
Wish you all the best!
Regards,
Mrinal