If there is no instruction, you have to write your name first.
Caution: Explosive. Handle with care.
'Idhuvum Kadandhu Pogum "
Even this challenging situation would ease
The title of this thread "Which method to follow at present-Sur name first or last name first?"
Surname or last name are same. There should be real name in place of last name.
Honesty is the best policy.