B1/B2 visa question

[ana.fds]

I have a B1/B2 visa. I need to travel to USA for my brother's wedding which is on August 31th.
Also, my work manager asked me to file my H1 visa. And start working from October onwards at USA.

I had few concerns and wanted to clarify:
1. If I apply for H1, will my B1/B2 visa get lost/removed?
2. After I go for my brother's wedding, do I need to come back to India and then go back using the H1 visa?

Thanks a lot in advance.

 

[Triple Citizen]

That approach would be best. Once your H-1B petition is approved, apply for an H-1B visa in India and then re-enter the US using that visa.

I2. After I go for my brother's wedding, do I need to come back to India and then go back using the H1 visa?