You asked about NREC earlier but I failed to set up email alerts correctly (and that post is locked now) so I'm replying here if that's ok.
Hiring process takes around a month or two, depending on how schedules line up. There would be a basic phone/skype screen, then a in-depth technical screen on your areas of expertise, and finally an on-site interview. We try to get back to you on each stage within a week of each stage.
We have a bunch of employees that are on H1-B's right now. Let me know if you have any other questions and sorry for the late reply!