Rule 2 — Definitions.
Sub-rule (1) fixes four definitions that hold throughout the rules, unless the context otherwise requires. "Act" means the Income-tax Act, 2025 (30 of 2025). "Authorised bank" means any bank as may be appointed by the Reserve Bank of India as its agent under section 45(1) of the Reserve Bank of India Act, 1934 (2 of 1934), so the identity of those banks is settled outside these rules, by the Reserve Bank. "Form" means a Form in Appendix III appended to these rules. "Section" means a section of the Act.
Sub-rule (2) supplies what sub-rule (1) leaves out. Words and expressions used in the rules and not defined in them, but defined in the Act, carry the meanings respectively assigned to them in the Act. Nothing in the rule creates a liability or a procedure; it only settles what four recurring words mean when any other rule uses them.
The rules are drafted in shorthand: they say "section 263", "Form No. 17", "the Act", hundreds of times without repeating what those refer to. Rule 2 supplies the referent once. Sub-rule (2) then avoids a second layer of definitions by borrowing the Act's own, so a term does not carry one meaning in the section and another in the rule made under it.
When a rule anywhere in this set says "section", it means a section of the Income-tax Act, 2025, and not of any other enactment, unless that rule names the other enactment; rule 2(1)(d) is what makes that true. "Form" is narrower than it looks: rule 2(1)(c) confines it to a Form in Appendix III appended to these rules, so a document that is not in Appendix III is not a Form for the purposes of any rule. The list of authorised banks is nowhere in these rules and is not for the Department to settle; it follows the Reserve Bank's appointment under section 45(1) of the Reserve Bank of India Act, 1934. All of this yields to the opening words "unless the context otherwise requires".
A rule requires a sum to be paid into an authorised bank. The taxpayer's own bank will not do merely because it is a bank: rule 2(1)(b) makes an authorised bank one appointed by the Reserve Bank of India as its agent under section 45(1) of the Reserve Bank of India Act, 1934. The rules themselves name no bank, so the answer has to be found in the Reserve Bank's appointments.
You never meet rule 2 as an obligation. You meet it every time another rule says "in Form No. ..." or "under section ...", because rule 2 is what makes those references point where a reader assumes they point.
"Form" means a Form in Appendix III appended to these rules;
Words and expressions used herein and not defined but defined in the Act shall have the meanings respectively assigned to them in the Act.