nishokie,
That is why your attorney is asking you to wait for your PCC. There is no point in applying now because you do not know when you will attend the interview.
Hence, it is better to wait till your category becomes current and you hear about your interview.
However, if you dont mind spending money, you may apply and obtain the PCC now and hope to get the interview within one year from its issue ( or 6 months in case of Mumbai).
INCASE, you dont get your interview within one year, you will have to spend money and reapply for the PCC.
Applying now may be beneficial to you because let the Consulate take 45 days to issue you now. And in case you have to reapply to the same consulate later, hopefully they will issue you the new PCC within 10 days , as they have already issued once.