Yes, the Vortex Strike Eagle 4-24x50mm Rifle Scope will be compatible with your 6.5 Creedmoor AR rifle. I would recommend using a high height scope mount like the Vortex Sport Cantilever 30mm Rifle Scope Ring Mount, found by using the link below:
https://www.opticsplanet.com/vortex-30mm-cantilever-riflescope-ring-mount-for-ar-15.html
On the Ruger Precision Rifles, you would be best served by a set of the 30mm Pro-Rings in High (1.26), or, one of the cantilever mounts, like the Pro-Series 30mm Cantilever!
MRAD stands for milliradians (or MIL for short) and is used as a system of measurement.
Because of the 50mm objective lens, high height rings will likely be required for most bolt guns. AR platform rifles should use extra high rings to obtain the proper centerline height. Email us at Techsales@opticsplanet.com and let us know what specific rifle you intend to mount this scope to, that way we can better recommend a set of rings that will work with your setup.
I own three of these with the MOA reticle and they do not have a zero stop.