How do I put 2 HTML exported games in same folder because index.html files have to be in a same folder?
Short answer: Put them in subfolders.
Long answer: It depends on what you are trying to achieve. Are you trying to make a webpage where you can choose between two games? If so, then you will need a main page with a single index.html file with links to the two subfolders containing your individual games.
A server will only load one index.html file per directory.