Yeap Ji...U can give a try. My sister with her 5 months old daughter was here in May 2008, including both my parents ( my parents alreday had visa 6 months ago, and my sister just gave a shoot after 6 months). They gave her and my vhanji 5 years multi entry visa. Documents that I scaned and send her were -

1. A letter to consular stating why her visit was imporatnt to me.

2. Letter from my employer, stating my annual income.

3. Tax return from previous year

4. My diploma college certifactes.

5. (This was a made up thing, although she said they didn't even bother to ask nor look at this )-. A marriage card that I was able to generate using computer, marriage venue and address and even temple information.........

Questions that were asked to my sister: How long is your bother leaving in USA? What he does? When was the last time you saw him? What your husband does? Where is he now? ( my vinajue was here too before them) How many other kids do u have and where are they? WHat you do by profession?....

Now, it all depends upon ur bothers, how impressive he will be while giving the interview. Make sure he carries each and everything during interview to proove that he will return back Nepal. The most important thing I think is his job status and pay income back home.