You need a LIBNAME statement to point to the library where your data exist or should be saved,
like:
libname gct "...path to the library ...";
also: in proc sql, when you use a form of X.y - then
X should be defined as reference to input dataset an
y is a variable name.
Your code:
SELECT GCT.DemCluster, GCT.DemGender, GCT.DemReg, GCT.DemTVReg
would be interpreted as: GCT is a reference
while DemGender DemReg DemTVReg - are variables in your input
defined by:
FROM GCT.ORGANICS;
that should be changed into:
FROM GCT.ORGANICS as GCT;