Go for an automatic petrol car with ADAS, and do not let the ethanol blending concern push you towards diesel. Your low annual running does not justify the higher purchase cost, higher maintenance, and potential DPF-related issues that come with modern diesel cars.
Diesel engines are at their best when they are regularly driven on highways and cover higher annual mileage, which is not your usage pattern.
On the ethanol question, modern E20-compliant petrol engines are engineered with a margin of safety. Manufacturers design fuel systems, seals, and components to tolerate slightly higher ethanol blends than the official limit. The main impact of higher ethanol content is a small drop in fuel efficiency, not reliability or engine damage. There is currently no official roadmap beyond E20, and if India does move to E25 or E27, it is likely to be a gradual transition, giving manufacturers time to adapt. Your car will not suddenly become incompatible.
Within your budget, the Kia Seltos IVT is the best fit. It offers ADAS, a proven petrol automatic powertrain, and a strong value proposition. It is also a comfortable car with plenty of space and a premium cabin. This Kia car has a 1.5-litre naturally aspirated engine paired with a silky-smooth IVT transmission, making it exceptionally easy to drive in traffic.