Error(s):

source_file.c: In function ‘FindMax’:
source_file.c:6:17: error: expected expression before ‘int’
     for(int x;x<int n;x++)
                 ^
source_file.c:7:21: error: ‘n’ undeclared (first use in this function)
         for(int y;y<n;y++){
                     ^
source_file.c:7:21: note: each undeclared identifier is reported only once for each function it appears in
source_file.c: In function ‘main’:
source_file.c:32:12: warning: format ‘%lf’ expects argument of type ‘double’, but argument 2 has type ‘int’ [-Wformat=]
     printf("Maximum Value of the Array is %lf",FindMax(A));
            ^
source_file.c:30:9: warning: unused variable ‘n’ [-Wunused-variable]
     int n=3;
         ^
source_file.c:29:9: warning: unused variable ‘Rz’ [-Wunused-variable]
     int Rz[9];
         ^
source_file.c:28:9: warning: unused variable ‘Cz’ [-Wunused-variable]
     int Cz[9];
         ^
source_file.c: In function ‘FindMax’:
source_file.c:11:25: warning: control reaches end of non-void function [-Wreturn-type]
                         }
                         ^