Although both frameworks are used for backend frameworks and both are appropriate for web projects. While Ruby on Rails is a precise framework for early stage startups or organizations, Django is better for large enterprises. It is because Django has the ability to handle multiple databases in a more standardized way.
Ruby on Rails is an awesome web framework to use, from simple to complex software projects. It has all the best elements that can do the job just as or even better than other frameworks.
If you are delivering a new application for the web it is good to develop it in Ruby, Python, NodeJS or GoLang. It is up to you to choose the appropriate framework according to your needs and preferences.