Get the Nth Term in the Fibonacci Sequence
A few points about improving code


It seems that your naming convention for constants is to use a capitalized identifier. If so, that should be applied consistently for all constants including inputFailure.
The loop in the function getTermCount can be simplified. A for-loop is clearer IMO.
The output of getNthFibonacciTerm is actually off by one term (assuming the sequence starts with 0 at index 0). It outputs 1 for input 3. The conditional checks before the loop could also be avoided to simplify the code.
Since the Fibonacci sequence is non-negative, the output could use an unsigned integer to allow slightly larger inputs.

About input range: since the output exceeds the limit of unsigned long long when the input is over 93, I do not see how it can be accurately represented unless you try to implement representations of big integers yourself in C.
About performance: there are several \$\Theta(\log n)\$ algorithms for computing Fibonacci numbers for a given input \$n\$. If you want that, here is a list of all algorithms.


Here is an improved version:

#include &lt;stdio.h&gt;
#include &lt;stdlib.h&gt;

static const int MinimumTerm = 0;
static const int MaximumTerm = 93;
static const int MaxTries = 3;
static const int InputFailure = -1;

static int getTermCount()
{
    const char *fmtstr = "Please enter an integer value between %d and %d\n";

    for (int count = 0; count &lt; MaxTries; count++)
    {
        int term;

        printf(fmtstr, MinimumTerm, MaximumTerm);    // IMO it is fine to just output to stdout before all attempts fail
        scanf("%d", &amp;term);
        if (term &gt;= MinimumTerm &amp;&amp; term &lt;= MaximumTerm)
        {
            return term;
        }
    }

    return InputFailure;
}

static unsigned long long getNthFibonacciTerm(int term)
{
    unsigned long long nthValue = 0;
    unsigned long long nextValue = 1;  // (n+1)th value, you may find a better name for that

    for (int termCount = 0; termCount &lt; term; termCount++)
    {
        unsigned long long newValue = nthValue + nextValue;
        nthValue = nextValue;
        nextValue = newValue;
    }

    return nthValue;
}

int main()
{
    int term = getTermCount();
    if (term == InputFailure)
    {
        fprintf(stderr, "Invalid Input\n");
        return EXIT_FAILURE;
    }

    printf("The %d term of the Fibonacci Sequence is %llu\n", term, getNthFibonacciTerm(term));
    return EXIT_SUCCESS;
}