I have a simple project Its on Ruby on Rails How to open it

Question

I have a simple project given by someone i have to work on it, I have netbeans installed on my system this project is of Ruby on Rails , I have open the project using the net beans and I have resolves the issues from the project by right clicking and then resolve project issues , Now when i click the run button it says 

"Start file must be a valid file"

I have different folders in the root like

Sources

Site Root

Important Files

npm Libraries

Bower Libraries

Remote File

how to set the start up folder/file in netbeans and which file must be the start up file