Thanks for all the advice.
I am going to check it out this weekend.
Will let you guys know what the story is about the offset.
But I have an idea that it is not the rims.
I bought them as a set of 4.
I also phoned the place where I bought them and they informed me that all the rims they sell as a set, the whole set will have the same offset.

It is just strange to me that this fault can be made at the factory.
The car was not in a accident and I checked everything to make sure about this.
Everything is spot on.
Those brackets that are whelded onto the diff looks like they are not correctly placed causing the diff to be offcentre by about 1cm to the right.(Looking at the back of the car).

It is not a major problem in town.(Low speed)
Just that I want to drive my datsun on the highway soon and now I cannot.
Our roads here have sometimes dips in them and at 100 to 120km/h the tyre will go into the body and either shred my tyre to pieces or destroy my wheel arch where it is scraping.