Kindly correct the following sentences
Most of them are not be working tomorrow
Most of them will not be working tomorrow
Most of them are not working tomorrow [delete "be"]
Most of them will not be working tomorrow
This one is correct.
The two sentences are expressing the same idea, more or less, with a very subtle difference in the "probability level". "Will", in theory, expresses a prediction, while the progressive aspect ("are not working") expresses more certainty.
Thank you for your kind information!