Maybe you want to have a look at the following project I found by using google.

https://github.com/peatio/peatio

It's open source and based on ruby on rails.
Regarding their readme it's a full featured exchange which is already used for some exchanges, so at least it does look like something legit.

Just remember, that running an exchange is more than just installing a software on a web server....

• You need developers who understand the source code to be able react fast in case of software bugs, or just to implement features you need but are not available in the current code base
• You need security experts to secure your servers, do security audits or handle attacks to the server
• You need people with knowledge how high availability servers need to be set up and maintained
• You need people who maintain the full nodes of all cryptos you want to provide on the exchange
• You need people to guarantee 24/7 support

And there are for sure lot more tasks which need to be done.

I don't know how experienced you team is, but if you don't have enough knowledge it's quite likely that you mess something up and you loose the funds of your customers.

Edit:
Just saw, that there is not much happening on github. The latest changes beside the readme are already 3 years old.
So as there is no ongoing maintenance of the software, if you plan to use it, you should really have your own development team to continue the project.