Can I change client after 221g was issued

Hi,
My H1-B was approved last year for 3 years which is valid till 2022 march.
I came to India last year for family emergency.
Due to covid I couldn’t go back. Last week I dropped my documents for visa stamping at Bangalore VFC but 221g white slip was issued asking me to appear to interview in person when this ban lifted(after DCE 31 i guess) with the client letter and SOW, passport returned. Now my question is my client will not wait until December so Can i change client get the new LCA, Amendment and appear visa interview submit new documents with this 221g.

Do I have to withdraw 221g and then apply for new visa appointment with new petition number or Can i walkin directly once the amendment is approved for new petition. Please suggest thank you…