Open up IIS install Rewrite module
then navigate to roo
Your site-> URL Rewrite -> Add new Inboud Blank Rule (This ideally should be first in the top level) then
Requested URL -> Matches the Patter
Using -> Regular Expression
Patter -> ^$
Action -> Action Type – > Redirect
Redirect URL -> Your Site to which you want redirect the root (This can be a sub folder)
Redirect Type (301) Permanent this means that the browser will keep the info and will no need to make a request next time to your server.
Tick – Stop process other rules.