-------changes to structures.h ( only added an int reg and int wait which are indexes of your registered and waitlisted students and the method declaration below...)
typedef struct _Course {
	int courseCode;
	char *courseName;
	char *courseDesc;
	Student *registeredStudents[25];
	Student *waitlistedStudents[25];
	int reg;
	int wait;
} Course;


void registerStudentList(int max, Course courseList[], Student studentList[]);


--------- main file:

int main() {

	srand(time(NULL));

	Student studentList[] = {
		{ NULL, "Doctor", "Doom" },
		{ NULL, "Lex", "Luther" },
		{ NULL, "Cat", "Woman" },
		{ NULL, "Two", "Face" },
		{ NULL, "Red", "Skull" },
		{ NULL, "Doctor", "Octopus" },
		{ NULL, "Captain", "Cold" },
		{ NULL, "Death", "Stroke" },
		{ NULL, "Harley", "Quinn" },
		{ NULL, "Dead", "Shot" },
		{ NULL, "Poison", "Ivy" },
		{ NULL, "Omega", "Red" },
	};

	initStudentID(MAX_STUDENTS, &studentList);

	Course courseList[] = {
		{ NULL, "C Language", "Programming in C without an IDE", NULL, NULL, 0,0},
		{ NULL, "Web Programming", "Websites from front to back", NULL, NULL, 0,0},
		{ NULL, "Data Structures", "Handling data efficiently with Java", NULL, NULL,0,0},
	};

	initCourseCode(MAX_COURSES, &courseList);

	registerStudentList(MAX_STUDENTS, &courseList, &studentList);
	registerStudentList(MAX_STUDENTS, &courseList, &studentList);
	printCourseInfo(MAX_COURSES,&courseList);

	return 0;
}


--------- additions to your print file or whatever you called it:

void printCourseInfo(int max, Course courseList[]) {
	int i, j;
	for (i = 0; i < max; i++) {
		printf("%03d %s %s\n",courseList[i].courseCode,courseList[i].courseName,courseList[i].courseDesc);

		printf("Registered Students:  %d/5\n", courseList[i].reg);
		for(j = 0; j < courseList[i].reg; j++){
			printf("%d -", courseList[i].registeredStudents[j]->studentID);
			printf("%s %s\n", courseList[i].registeredStudents[j]->Name.first, courseList[i].registeredStudents[j]->Name.last);
		}
		printf("\n");
		printf("Waitlisted Students:  (%d)\n", courseList[i].wait);
		for(j = 0; j < courseList[i].wait; j++){
			printf("%d -", courseList[i].waitlistedStudents[j]->studentID);
			printf("%s %s\n", courseList[i].waitlistedStudents[j]->Name.first, courseList[i].waitlistedStudents[j]->Name.last);
		}


		printf("\n\n");
	}

}

void registerStudentList(int max, Course courseList[], Student studentList[]){
	int i;
	int courseIndex;
	for(i = 0; i < max; i++){
		courseIndex=rand()%3;
		if(courseList[courseIndex].reg < 5){
			courseList[courseIndex].registeredStudents[courseList[courseIndex].reg] = &studentList[i];
			courseList[courseIndex].reg++;
		}
		else{
			courseList[courseIndex].waitlistedStudents[courseList[courseIndex].wait] = &studentList[i];
			courseList[courseIndex].wait++;
		}
	}
}
--------------