Dear applicant,

if you`re talking about filling form, irrespective of the exam, while filling the form you will get an option to choose catagory. After that either the same page asks for uploading the scanned copy of your caste certificate or in some other cases after the form filling, you need to go to another page to attach all necessary dosuments, including your caste certificate. If you`re talking about counselling, after you`ve got your rank card, while registering for that couselling orecedure, you will need to fill up the form and attach the documents specified in instruction.

Hope it helps.

Good luck!