Hi,
I got H1B from the company and I traveled to US and came back to India. Recently I had done my H1B Cap Excempt . Now I moving to another company , can the old company can cancel the visa/ petition ?
They can withdraw the approved petition. However, as long as you know the receipt number or have copy of the approval notice, another employer can still file cap-exempt petition for you.
They can also ask you to submit passport and then send it to consulate for visa stamp cancelation. They cannot cancel the visa stamp until they get physical custody of the passport.
Lot of companies just withdraw the petition and not worry about the passport.