6R3AR5K101M06X5C is a capacitor made by APAQ, a manufacturer out of Taiwan. Digi-Key Electronics does not currently carry APAQ products but we do have some suitable crosses to consider.
UMR0J101MDD is the most affordable cross. If more options are desired the following link provides a short list of other options:
Each of these are suitable for drop in replacement differing only in height at 6mm vs 5mm.
The following information is taken from the APAQ datasheet for the AR5K series which can be accessed here.
If there are any questions, please reply to this post and we will be happy to address them.