Concept:
The Negotiable Instruments Act, 1881 defines and regulates instruments like promissory notes, bills of exchange, and cheques.
Step 1: Section 6.
Section 6 specifically defines a
cheque as a bill of exchange drawn on a specified banker and payable on demand.
Step 2: Evaluate options.
- Bills of Exchange $\rightarrow$ Defined under Section 5 (incorrect)
- Cheque $\rightarrow$ Defined under Section 6 (correct)
- Promissory Note $\rightarrow$ Defined under Section 4 (incorrect)
- None $\rightarrow$ Incorrect
Step 3: Conclusion.
Thus, Section 6 deals with cheque.