good morning farhan!!

as on when you are filling the form caste certificate isnt mandatory!

during the application filling process you neednt have the caste certificate with you but after writing exam and when results are declared-during the counselling process you would be asked to submit the caste certificate form.

please make sure that by then(counselling process) you have caste certificate original one in hand.

for more details regarding the application process please see the following links :

https://bschool.careers360.com/articles/ap-icet-application-form

https://bschool.careers360.com/articles/ts-icet-application-form

all the best

thank you