NeuroStars.org is a platform similar to StackOverflow but dedicated to neuroscience and neuroinformatics. If you have a problem or would like to ask a question about how to do something in Nipype please submit a question to NeuroStars.org with a nipype tag.
All previous Nipype questions are available here: https://neurostars.org/tags/nipype
gitter.im stands under the motto 'where developers come to talk'. It is a place where developers change thoughts, opinions, ideas, and feedback to a specific software. Nipype's gitter channel can be found under https://gitter.im/nipy/nipype. Use it to directly speak with the community.
github.com is where the source code of Nipype is stored. Feel free to fork the repo and submit changes if you want. If you found a bug in the scripts or have a specific idea for changes, please open a new issue and let the community help you.