Hey!

Tell your friend to visit this site :

Examinations (testservices.nic.in) (https://testservices.nic.in/ExaminationServices/)

And choose CTET here, a new window will appear where he/she will find a tab "Forgot application number", click on it. A new page will appear where at bottom right corner there is a tab "Forgot application number", click on it again. Fill the required details such as father name, mother name and date of birth; copy the security pin (mentioned in the picture) then click on get application number.

Thankyou