If 12 eggs cost ₹ 18, what is the cost of 9 eggs?

Given that the price of 12 eggs is ₹ 18, we divide the total price by the number of eggs to find the price of one egg.

$$\text{Price per egg} = \frac{₹ 18}{12 \text{ eggs}} = ₹ \frac{3}{2}/\text{egg} = ₹ 1.50/\text{egg}$$

Multiply the price of one egg by 9.

$$\text{Price of 9 eggs} = ₹ \frac{3}{2}/\text{egg} \times 9 \text{ eggs}$$ $$\text{Price of 9 eggs} = ₹ \frac{27}{2}$$ $$\text{Price of 9 eggs} = ₹ 13.50$$

The price of 9 eggs is $\boxed{₹ 13.50}$.