[Solved] Recursive implementation of Fibonacci function

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I pasted your code on https://tio.run/#c-gcc, and here’s the result:

main prototype

.code.tio.c:3:7: warning: ‘main’ takes only zero or two arguments [-Wmain]
   int main(int fib) {
       ^~~~

the main function prototype is int main(void) or int main(int argc, char *argv[])

Since you want user to input a number, you can choose the first form.

count type

.code.tio.c: In function ‘main’:
.code.tio.c:7:5: error: ‘count’ undeclared (first use in this function)
     count = 0;  // counts the number of times the function is called
     ^~~~~

You must give a type to count variable, like

int count = 0;

fib_rec declaration

.code.tio.c:8:12: warning: implicit declaration of function ‘fib_rec’ [-Wimplicit-function-declaration]
     return fib_rec(n, &count);
            ^~~~~~~

You have not declared the function before using it.

You can declare it this way: int fib_rec(int n, int *count) for instance before the main definition.

printf usage

.code.tio.c: In function ‘fib_rec’:
.code.tio.c:21:15: warning: passing argument 1 of ‘printf’ from incompatible pointer type [-Wincompatible-pointer-types]
       printf (count);
               ^~~~~

The printf function ask for some formatting. If you want to display a integer value, use %d:

printf("count value is: %d\n", count);

incompatible pointer type

.code.tio.c:22:27: warning: passing argument 2 of ‘fib_rec’ makes pointer from integer without a cast [-Wint-conversion]
       return fib_rec(n-1, *count)+ fib_rec(n-2, *count);
                           ^~~~~~

Here count is already a pointer on integer, * is unnecessary:

return fib_rec(n-1, count)+ fib_rec(n-2, count);

display of computed value

Your code return the computed value, but doesn’t display it.
To do so, replace return fib_rec(n, &count); with 

printf("fib_rec(%d) = %d\n", n, fib_rec(n, &count));
return 0;

So the corrected code could be:

#include <stdio.h>

int fib_rec(int n, int *count);

int main(void) {
    int n;
    printf("enter n\n");
    scanf("%d",&n);
    int count = 0;  // counts the number of times the function is called
    printf("fib_rec(%d) = %d\n", n, fib_rec(n, &count));
    return 0;

}

int fib_rec(int n, int *count)
{
    int b=0,c=1;
    *count = *count +1;
    if(n<=1)
    { 
       return n;
    }
    else
    {
      printf ("count: %d\n", *count);
      return fib_rec(n-1, count)+ fib_rec(n-2, count);
    }
}

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solved Recursive implementation of Fibonacci function