Update the function calculateTax to calculate the income tax for a given salary and age group in a fictional country. The function should consider the salary amount and the age of the individual to determine the tax rate.
The function parameters are,
- salary (number): It represents the annual salary of the individual in the local currency.
- age (number): It represents the age of the individual.
The income tax is calculated based on the following criteria,
For individuals aged 60 years or below,
- No tax for salaries up to ₹2,50,000.
- 5% tax for salaries above ₹2,50,000 and up to ₹5,00,000.
- 10% tax for salaries above ₹5,00,000.
For individuals aged above 60 years,
- No tax for salaries up to ₹3,00,000.
- 5% tax for salaries above ₹3,00,000 and up to ₹5,00,000.
- 10% tax for salaries above ₹5,00,000.
The function should return a string indicating the tax amount based on the salary and age, for example, "Tax amount is ₹X", where X is the calculated tax.