C4D has an upper limit of 16,000 pixels in both directions, but a still image, at that size, will take a very long time to render, on a single machine.
Here is the link to a tutorial on setting up a "Tiled Camera" for rendering large stills, in C4D.
This how you how to break a single-frame into "Tiles". Each tile can be rendered on a separate render-node, allowing multiple render-nodes to work in parallel, on all the tiles.
Prepare the Scene File for Tile Rendering
1. Load your scene file with all your standard settings and have a camera already set up and ready to render.
2. Open the content Browser and find the "Tiled Camera.c4d" preset. This can be in different locations depending on the version of C4D you are using, you can use the search tool to locate it.
3. Drag the Tiled Camera to the Objects list.
4. With the Tiled Camera selected go to the User Data tab and adjust the "Tiles per Axis" to something to 4 or more depending on how complicated your scene file is. (More on this below)
5. Drag your Current camera (the view you actually want to render to the "Reference Camera" field.
6. Turn on "Use Tiling"
7. Change your Render Settings frame range to according to the description below
8. Finally divide your height / Width by the number of tiles you specified in the Tiled Camera. Be sure to divide by this number, NOT the total number of ALL expected tiles. For example: If you specified 4 tiles per axis, you want to divide by 4, not 16.
Tiles Per Axis / Frame Range
The "Tiles per Axis" will vary depending on how complicated/large your scene file is. A value of 2 will output 4 square images. A value of 4 will output 16. This works in a X * Y grid, so 4 tiles on the X-axis and 4 on the Y-axis. (4x4=16 or 2x2=4). The frame range you choose will depend on this. If you use 4, that's 16 tiles, so your frame range will need to be set from 0-15. A value of 2 (4 tiles), then your frame range will be 0-3. (Frame 0 counts as the first frame). Once the tiles have been completed you will need to download and stitch them manually in Photoshop. Unfortunately C4D does not have a feature to do this manually.
Submit Your Render
1. Save / Upload your scene file
2. Be sure you choose the same frame range on the Super Render Farm website as you did in the scene file.