Important H1b Transfer and Maintainence of status question please advice

HI All/Seniors,

I have few important questions can someone who have gone through this answer please:

H1b Approved with Employer A till March 2021.

Also have Visa Stamping in Passport with Employer A till March 2021

Also have online I 94 updated showing my validity as March 2021 as i travelled to India last year.

Now I Joined Employer B in December 2018 and I am working on Employer B H1b Receipt notice after joining them on December 2018.

In March 2019 Employer A sent request to USCIS to withdraw Employer A petition.

If now Employer B petition is denied can i reapply new petition in premium again and continue staying in USA?

As i said on top i have online I 94 showing my validity as March 2021

Just having I-94 valid does not mean that you can stay in the country, you need to be properly maintaining status in US. Now, in general, you get a 60 days grace period, if your employment ends before the specified end date on the petition like in your case leaving employer A. It is slightly grey area and not sure how USCIS will count the grace period, either from the day the withdraw was sent by employer A. Also, the grace period is always a discretion of USCIS. You can always apply with other employer as consular processing, go out and come back, but staying within US, it can be tricky. I suggest you discuss with your attorney.