H1B travel back to US stamping after many months in India

Hi, I am currently on H1B in the US, I am being laid off, I have a new employer who is doing the visa transfer however they only want me to start working after transfer is approved and complete.

I expect this to take few months as currently there is no premium processing. Once they initiate the process and get the receipt, I plan to move to India for few months since I don’t know the exact timeframe it may take.

Let’s say it takes 6 to 8 months to get approved.

  1. When I come back, do I have to get my passport stamped with the new employers I-797? My current stamp is valid for 2 more years.
  2. Can I come back without getting the new stamp even if my previous employer withdraws their sponsorship?