For me RAII in the abstract is an object/resource-lifetime management strategy, such that creation and destruction of composite objects appear atomic wrt resources/objects held internally, as far as users of the object are concerned. Obviously it's good programming to try make objects atomic in this way when designing code.
C++ has implicit calls to constructors and destructors, which tie in to scoping. C doesn't have that, true, and requires explicit construction and destruction (you can still hide destruction behind refcounting, obv). It's often bad practice and/or a sign of a (quick)? hack when C code uses automatic allocating for non-trivial, composite objects.
Whether language support for implicit ctor/dtors tied with scoping is required for a practice to be called RAII, I don't know. I guess to a C++ person it does. Still, the general sentiment of RAII seems more widely applicable than C++.