H1b - 60 Day Grace period - Uscis Receipt notice questions

Hi,

I got laid off from company A on Sept 30th, and hence my 60 day grace period ends on 28th Nov. The Attorney said they are going to file and post my petition on 26th Nov. If my receipt comes by 28th Nov or on 28th Nov, then everything is good, or else I will have to leave the country right?

My I-94 has expiry till 2021

In a case where the receipt does not arrive by 28th of Nov and I have to leave US, Can I reenter US with the approved I-797 or do I need to stamp my visa by giving a visa interview?

Well, technically you will not have any status after your 60 days grace period. Also, you need to be aware the 60 days grace period is discretionary. Yes, technically, if USCIS receives the petition you may be covered…but it is slightly grey area here, the date of received by USCIS vs. Date of Receipt notice… As your I-94 is still valid, that also can play a part and you may not have to leave as well…
Discuss with your attorney and then take a call.

If you want to play it very safe, you can leave the country, get stamping and come back…