Step 1: Calculate Net Profit before Interest and Tax (EBIT)
Net Profit after Interest and Tax = \rupee4,10,000
Add: Tax = \rupee40,000
$\Rightarrow$ Profit after Interest but before Tax = \rupee4,10,000 + \rupee40,000 = \rupee4,50,000
Add: Interest on Debentures = 10% of \rupee15,00,000 = \rupee1,50,000
$\Rightarrow$ EBIT = \rupee4,50,000 + \rupee1,50,000 = \rupee6,00,000
Step 2: Calculate Capital Employed
Capital Employed = Non-Current Assets + Current Assets – Current Liabilities
= \rupee25,00,000 + \rupee7,00,000 – \rupee2,00,000 = \rupee30,00,000
Step 3: Calculate ROI
\[
\text{ROI} = \left( \frac{\text{EBIT}}{\text{Capital Employed}} \right) \times 100 = \left( \frac{6,00,000}{30,00,000} \right) \times 100 = \boxed{20%}
\]