"cluster bombs" are a bad translation of the French original - bundles of 10kg or 50kg bombs would have been more adequate. French aircraft in Indochina carried quite often these packages - variants of the pre-war "Paquetages Gardy 10kgx4", and similar (though somewhat different) from the German packages AB 500-A/4 SD 50frz and Bd frz 10. In fact the French air force still uses this system with the SAMP BL15 paquetage made of 4x60kg antipersonal bombs.
The most frequent bundles used in Indochina were made of 3 bombs: either 3x50kg DT2 on each bomb rack or 2 units in tandem of 3x10kg P each, on each bomb rack
It seems that there were even few cases where US made M26 clusters of anti-personal bombs were carried by French Bearcats
I must say that I have not seen a single photo of a French P-63 with these packages or with rockets, but, once again, this does not mean that they never carried them.
After verification, it appears that the the GCII/6 indeed tested rockets on its P-63C in Indochina, with very poor results, attributed to the impossibility to dive at at precise, fixed, angle. A trial of addressing the issue by mounting an artificial horizon instead of the collimator of the plane was a failure. I have not found data upon the number of rockets carried in these trials (3 under each wing as on the P-63A? or only 1 or 2 under each wing, instead of the regular bomb rack?)