There are a plethora of automatic petrol cars available within your budget. Given your monthly travel is just 200-300km, we will give less weightage to fuel economy and more weightage to driving comfort. As we don't know other preferences, here's a shortlist of the best options by body style -
Hatchback - Hyundai i20 IVT Asta (O), Citroen C3 X Shine AT
Compact sedan - Honda Amaze CVT ZX
Compact SUV - Nissan Magnite Turbo CVT, Renault Kiger Turbo CVT Emotion

