Yes, you can. However, you will need to ensure the machine where Redmine is running has enough resources to handle all those connections.
The Bitnami Redmine solution comes with MySQL and all the servers that the application needs to run. Once you install/deploy it, everything will be configured for you to use.
If you deployed a new instance in the cloud, they can use the public IP of the instance to access the application. If you deployed that locally using a native installer, they need to have access to your network to open the application in the browser. I understand you used the Windows installer, right? In this case, if the developers are not in the same network, you will need to forward the ports in your router so they can use your public IP to access the application