The whole idea of getting emploment based GC is, 'you have a permenant employment with the employer, who is sponsering you and will not become a public charge to the Govt'.
If you apply for the unemployement benifits now, you are declaring that you became 'public charge' which might trigger an RFE. The best thing is to find a same or similar job immediately and use AC21 (If you are past 180 days after filing 485).
