Dear Sir,
As per instruction kit point no 10 of Form 23AC:
Enter the SRN of Form 23B filed in relation to the appointment of the auditor who has audited the attached balance sheet, if available.If the SRN of Form 23B is not available or *** in case information by auditor to RoC in Form 23B is not required to be filed you may enter Z99999999.
Note:
*** Form 23B is not required to file for first auditors and I mentioned the same in earlier mail.
Further to this if SRN is not available then company can put Z99999999.
Warm Regards,Sheikhar Naik