Catalysis of the reaction: (25R)-3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-oyl-CoA + H2O + acceptor = (24R,25R)-3alpha,7alpha,12alpha,24-tetrahydroxy-5beta-cholestan-26-oyl-CoA + reduced acceptor.
(25R)-3alpha,7alpha,12alpha-trihydroxy-5beta-cholestan-26-oyl-CoA:acceptor 24-oxidoreductase (24R-hydroxylating) activity