They may be expecting you to do the transcode in Avid Media Composer.
If you only work in Adobe Media Encoder CC 2014-15, you can encode to Avid DNX 36 (must change the file type from QuickTime to Avid DNXHD MXF for the presets to become active). Press options to change the resolution to DNX 36 from the default 220. NOTE...this is creates MXF files that are OP1a, rather than OPAtom, which is the optimum format for Avid. Avid will still not be able to directly work with this media, but rather the editor will have to link via AMA and consolidate. Probably not what they want, but it can work. They may lose some of the metadata they want using this method.
I'd do this transcode in Avid if you can...even if it means getting the trial version of 8.4. It will work for a month. You will then be able to create media that works directly in Avid and create bins that refer to the media you create. Talk to your client about this before proceeding.