I have my H1 visa stamped in India. But my employer was unable to find a client to engage me in any work. So my H1 is not used for the last six months. Now, a new employer is interested in providing me a job. Can the existing H1 converted to the new employer? If yes, how long it will take.
Technically, there is no "conversion" of an H-1B from one employer to another. However, your potential employer can file a new H-1B petition for you. With premium processing (fast track), the new petition can be approved with 15 days of filing the petition. I am assuming you are in India now. If so, once the petition is approved, you can apply for a new visa at the embassy (this is the safest course to ensure admission into the U.S.). Of course, your new employer should engage an attorney to start and guide you through this process.