Was Jesus resurrected after or {within} three days of his death? Was Jesus resurrected after complete 3 days, or he resurrected in the third day?. I mean if he had been resurrected in the third day, this means that he had spent less than 72 hours before his resurrection.
As Lucian pointed out, people of the time would use inclusive counting. This means:

Jesus died and was buried before sundown. This is considered the first day.
The next day began at the following sundown. This is the second day. During that entire day Jesus was in the tomb.
The day after that began at the next sundown. This is the third day. On the morning of that day, i.e. the one after the second sundown following his death, Jesus is raised from the dead and encounters his followers at the tomb.

Thus Jesus is raised on the third day. It is less than 72 hours (indeed less than 48 hours) between his death and resurrection.