For appearing in the CUET (UG) , there is no age limit for the candidates. The candidates who have passed the class 12 /equivalent examination or are appearing in the examination, irrespective of their age can appear in CUET (UG) examination.
However, the candidates are required to fulfill the age criteria (if any) of the University / Institution / Organization in which they are desirous of taking admission.

For year of appearance in Class 12 / equivalent examination, relevant conditions of Universities / Institutions (as applicable) will be applied. The candidate must ensure his eligibility from the website of respective Universities / Institutions