Make a research

Where are your customers?
The answer to this question depends on your business. If you open a shop or customers come to you, the site of your enterprise defines your clients.
In case you visit the clients shop is opened in the city centre, it is possible to involve more customers. But you should know their location in order to make a targeted advertising campaign

The information which you are interested in can be received as a result of independent research of the area .Just have a walk in the neighborhood and note those features which should be considered in the course of the commercial activity. For example, where are your competitor`s shops situated ? How many the industrial enterprises, shops, consumer services are around.? Where there are lots of men and women in the streets? Pay attention to buildings: are they old or new? Inhabited or uninhabited? Type of houses: brick, block, panel etc.? Pay attention to passers-by: how many young people, people of middle age, pensioners? How are they dressed? Pay attention to marks of the cars parked at entrances of apartment houses and offices. Try to answer the question if there are many  garages in your area?
After conducting such research you can understand how many potencial customers live in your place. You will know better where your probable clients are.
It is woth trying to apply to local authorities an inquiry on social and economic structure of the given area. Perhaps, in this case you should pay for the information you are interested in.
This data will help you to make the final decision where to locate your company`s premise, especially if your  business is connected with reception of clients.