With all due respect, I would like to inform you that I am ________ (name), student of ________ (course name) having _______ (University roll number).
This email is in reference to the mishap happened on date __/__/_______(date). I would like to express my sincere apologies for the misconduct that I have caused in _________ (mention location). I feel so ashamed for doing this mistake and I regret for the same.
Once again, I am sorry for the this misconduct and I promise you that this will never happen again in future.
___________ (Contact details)