Here's an overview of the audit requirements for organizations approved under Section 80G: 

Mandatory Audit: Organizations approved under Section 80G 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 approved under Section 80G 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 80G can result in penalties and other consequences imposed by the Income Tax Department. It's crucial for organizations approved under Section 80G to adhere to the audit requirements and maintain proper financial records to ensure compliance with the law.

Overall, the "80G audit" refers to the audit process conducted for organizations approved under Section 80G of the Income Tax Act, 1961, to ensure compliance with income tax laws and regulations and maintain their eligibility for donors to claim deductions on their contributions.