Mistakes include:
Missing a ; after int i =0.
You are only printing 1 char at a time
There is no line feed (as per you requirement)
Unfortunately you cannot fix this without adding another loop to count the chars to print. I would do it like this (using your restrictions):
char str[] = "hello";
int iLength = 5;
for (int i=0; i<iLength; i++)
{
for (int j = i; j < iLength; j++)
printf("%c", (int)str[j]);
printf ("\r\n");
}