but couldn't understand why my tires would have this as it is a new car.
And as it is a "new" car, why did you change the tires already ?
And what brand/model/size tires did you put on it ?
If you put on wider skins, they might just do that......unless you can talk someone into changing the alignment slightly.
Some styles of tires are more prone to do that than others.
In addition to checking the alignment, you might want to search for
similar reports using the tire model as a search key.
I once had a set of Firestones, IIRC, where the second rib from the outside was the first place to wear. That was really strange.