Received notice under sec 133/6

133(6) notice for investment proof:
• Respond with available documents: bank statements, contract notes, property documents, and source-of-funds explanations. For investments without documents, provide alternative evidence (bank debits, broker statements, AIS).
• If an investment was made from undisclosed funds, consider ITR-U (if tax is payable and within time) before the AO initiates reassessment.
• Non-compliance: penalty Rs 10,000 per failure (Sec 272A(1)(d)), and possible best-judgement action.