Hello @VasanthM !
Thanks for reaching out!
There is no sample exam in Red Hat. You have some preliminary exams ( which is a good test before your actual real certification exam ) but not for EX221.
Refer this link for info on preliminary exam : https://www.redhat.com/en/services/training-and-certification/preliminary-exams
Also, preliminary exams are browser based remote exams and are not available at testing centres.
If you want to go for preliminary exams you need to purchase one like PE124 ( based on RH124 course ) or PE180 ( based on DO180 course ).
Please reach out to support team here for more clarifications : https://rhtapps.redhat.com/comments