Are we different or same?
Welcome to Psychology.SE.
When you ask

if two childs from different parents from different regions are kept in a completely empty room, do they behave same or different

that is a question which is heavily debated in Psychology. It all boils down to the nature vs nurture or nature vs environment shaping behaviour.
Your question is definitely not silly and as it stands, the answer is very much open to opinion but you can get some information on the debate from the link provided above.
See also:

https://en.wikipedia.org/wiki/Nature_versus_nurture
https://behavioralscientist.org/the-end-of-nature-versus-nurture/
https://www.goodtherapy.org/blog/psychpedia/nature-versus-nurture
https://www.softschools.com/examples/science/nature_vs_nurture_examples/482/
https://www.verywellmind.com/what-is-nature-versus-nurture-2795392