Maximum possibility of banknotes to keep into the given integer value
Don't use the for-case antipattern
You are using the for-case antipattern, which you should almost always avoid. Instead, find some way to simplify your code. For example, instead of hardcoding the denominations in the if-statements, put them in an array:
static const int denominations[] = {100, 50, 20, 10, 5, 2, 1};
static const int n_denominations = sizeof denominations / sizeof *denominations;

Then use it like so:
for (int i = 0; i &lt; n_denominations; i++) {
    count = 0;

    while (number &gt;= denominations[i]) {
        count++;
        number -= denominations[i];
    }

    printf(&quot;%d nota(s) de R$ %d,00\n&quot;, count, denominations[i]);
}