What modification of enginee is better, petrol or diesel

Hello. I am going to buy new car, Maruti Suzuki Ertiga. What do you think, what modification of enginee is better, petrol or diesel? Unfortunately, I'm not good in these things, it's my first car, so, it's make me feel a bit confused. My brother recommended prefer petrol car 'cause it's a best choise for using next 7-8 years. But I heard, diesel car're considered more ecological. So, what enginee is better?Please, help me to make this thing clear. Thanks.