Hello, Arumugan, good afternoon,
1. Why do you say that you cannot enter more than 250 anwer options?
2. I told you before: email validation -> regular expression.
As described in the manual:
/^(\w[-._+\w]*\w@\w[-._\w]*\w\.\w{2,3})$/
Of course you are free to adapt it.
See attached sample with 350 answer options and email validation.
Kind regards
Joffm
But to answer your question:
Of course it is possible to modify the php code.
You have the original code, so why not change it. Develop whatever you want.
But remember: Updates will overwrite your new code.