At the beginning of the match does a robot have to start fully in the 5 point zone?
Please review the Q&A Usage Guidelines before posting, specifically point 1, "Read and search the manual before posting any questions".
Let's take a look at rule SG1, which defines the starting conditions for all Robots:
<SG1> At the beginning of each Match, each Robot must be placed such that it is touching the Alliance’s Starting Bar, not touching any Scoring Object other than those permitted by SG2 and not touching another Robot.
There are no restrictions other than those laid out by SG1. So, to answer your question, no, a Robot does not necessarily have to start completely within the 5 point zone.