Here's an overview of the audit requirements for organizations registered under Section 12A: 

Mandatory Audit: Organizations registered under Section 12A are generally required to undergo an annual audit of their accounts. This audit is conducted to ensure that the organization's financial statements accurately reflect its financial position and comply with relevant laws and regulations.

Chartered Accountant (CA) Audit: The audit of organizations registered under Section 12A must be conducted by a practicing Chartered Accountant (CA) in India. The CA examines the organization's financial records, transactions, and internal controls to express an opinion on the fairness and accuracy of the financial statements.

Income Tax Return Filing: Following the completion of the audit, the organization must file its income tax return with the Income Tax Department. The audit report prepared by the CA is typically submitted along with the income tax return.

Due Date for Audit and Filing: The due date for conducting the audit and filing the income tax return varies depending on the organization's structure and other factors. Generally, the audit must be completed and the income tax return must be filed within a specified period after the end of the financial year.

Compliance and Penalties: Non-compliance with the audit requirements under Section 12A can result in penalties and other consequences imposed by the Income Tax Department. It's crucial for organizations registered under Section 12A to adhere to the audit requirements and maintain proper financial records to ensure compliance with the law.

Overall, the "12A audit" refers to the audit process conducted for organizations registered under Section 12A of the Income Tax Act, 1961, to ensure compliance swith income tax laws and regulations and maintain the organization's tax-exempt status for its charitable activities.