Scientific research association approval under income tax rules requires Form No. 17, jurisdictional filing, and prescribed renewal timing. Approval for a scientific research association under section 45(4)(b) is sought in Form No. 17 from the Commissioner of Income-tax having jurisdiction over the applicant, ordinarily during the financial year immediately preceding the tax year from which approval is sought. A relaxed filing window applies in specified cases, including the transition year from AY 2026-27 and the year of incorporation. Renewal may be sought at least three months before expiry of the existing approval.