When preparing your comps for 3d, there are no specific 'real-d' things that need to be addressed, this is because theaters use many different systems for 3d projection. Specifically doing some comp/grade change just for real-d isn't a good idea and isn't needed. Common 3d systems include:

Real-D - passive circular polarized glasses

Dolby 3d - passive interference filter glasses

Active shutter glass systems

There are also auto-stereo displays that don't require glasses and other ways of viewing 3d images, such as the cross-eye free-viewing method.

if there are any content changes that are needed for a viewing method (anaglyph for example) that will be handled by someone else, not the vfx vendor, so don't worry about it.