Considering your monthly commute of 1800 km, the Tiago XT CNG (2024, 17,000 km) at ₹6.1 lakh offers good fuel economy and low running costs, making it a practical choice. However, ensure the vehicle is thoroughly inspected and service history verified—if all checks out, it’s a solid deal, though comparing with similar CNG options like the Wagon R or Swift may help confirm value.