Under Section 54 of the Income Tax Act, to claim exemption on Long-Term Capital Gains (LTCG) from selling a residential house, you must either buy/construct a new property or deposit the unutilized gains into the Capital Gains Account Scheme (CGAS) before the due date of filing ITR.
If your trading turnover or total income triggers a Tax Audit (under Section 44AB), your ITR filing due date automatically shifts from July 31 to October 31 (with audit report due by September 30). If tax audit does not apply, the default date remains July 31 (though your CA may be referring to a specific extension or business return schedule).
You get 2 years to purchase or 3 years to construct a new house from the date of property sale. You do not have to complete the actual property purchase right now. To claim the tax exemption in your current ITR, any capital gain amount not yet spent on the new property must be deposited into a CGAS account on or before your applicable ITR filing due date.
Ask your CA to confirm whether your F&O/intraday turnover mandates a Tax Audit or if you are filing under the Presumptive Taxation Scheme (Section 44AD). This determines your exact ITR due date (July 31 vs. October 31).
Do not wait until the last day. CGAS accounts can only be opened at authorized public sector banks (like SBI, PNB, etc.) via physical branches.
If you fail to deposit the unutilized gain into CGAS on or before your statutory ITR due date, you permanently lose the Section 54 exemption for that unutilized portion, and it will be taxed at 20% (plus applicable surcharge/cess).