Step 1: Nature of debentures.
Debentures represent borrowed funds repayable after a long duration.
Step 2: Classification.
In company Balance Sheet (as per Schedule III, Companies Act, 2013):
- Share capital → Shareholders’ funds.
- Debentures → Non-current liabilities → Long-term borrowings.
Step 3: Conclude.
Thus, debentures are shown under Long-term borrowings.
Final Answer:
\[
\boxed{\text{Long-term borrowings}}
\]