What is the name of the condition where you feel like you have been somewhere before? It happens many times when you visit a place you have never been before, you feel subconsciously you have been there already. And the events and people you are meeting and experiencing have already taken place sometimes back and you are just re-experiencing it.

What is this condition called? Is there any scientific study on the same?
The term is typically called déjà vu..

There's a section on wikipedia discussing scientific research.

Brown (2003) looks like a good starting point for a more rigorous scientific analysis.

Kusumi (2006, PDF) has another scientific review article on the topic.

References


Brown, A. S. (2003). A review of the déjà vu experience. Psychological bulletin, 129(3), 394.
Kusumi, T. (2006). Human metacognition and the déjà vu phenomenon. Diversity in cognition: Evolution, development, domestication, and pathology, 302-314.
http://www.educ.kyoto-u.ac.jp/cogpsy/personal/Kusumi/dejavu.pdf