Hard luck mate! Still you can try doing the following (absolutely in air, don’t know if any of it would work):
1. If the date was only a mistake in filling the form and you can demonstrate that you actually joined the new office earlier than that, then ICAI may consider.
It is not too difficult to prove the date when you joined...your time sheets, expense bills if any, if you sign a attendance register or something or if there is an access card system in your office, which shows you were working before the date mentioned in the form, you might get lucky.
2. Try to see if you have comp-off days which you can knock off against the excess days and bring the date within, what is allowed for the attempt.
3. Along with 1 + 2, speak to ICAI explain your case in details, follow up and try to reach the highest level you can.