be willing and capable to participate at the World Finals AND
be enrolled in some course of the university you are competing for.
Furthermore, you are only allowed to compete for one university and cannot have participated in
two or more World Finals OR
five or more Regional Contests
Lastly you need to
have started your studies no sooner than (current year - 4) OR
be born (current year - 23) or later.
If both or the previous conditions cannot be met you can petition the ICPC Eligibility Committee if you have not completed more than the equivalent of eight semesters of full-time study as of the date of the regional contest. Have a look at the ICPC rules website for more details.