Question about Rollei QAL-50 Quick release plate

I just ordered a C6i tripod and the QAL-50 a few weeks ago, both are original Rollei and therefore fit.

If the original ball head with the Arca Swiss compatible clamp is mounted on the C6i, then yes. Any other Arca Swiss compatible plate should also fit (Sirui, Benro, kiwifotos and others). It does not have to be from Rollei. Rollei doesn't make them themselves anyway.