in c, is it possible to call a function inside another function which will be called by the main function?

Answer 1

Definitely! You can do it like this:
#include <iostream>
using namespace std;

void bar() {
cout << "hi!";
}
void foo() {
bar();
}

int main() {
foo();
return 0;
}

Answer 2

Of course, the same thing which Rowsej did can be done in pure C language as well.

Answer 3

its exactly c++ not c