I am applying for H1B for the next fiscal year 2020-2021. That will be my last chance. Can I do two petitions with two different employers on same client letter?
You can have two employers, but you would need two separate petitions.
You can find more information here: https://immigrantly.com/2014/11/25/can-i-have-two-full-time-jobs-under-concurrent-h1b/