what are the docs required for counselling of jossa 2017? (any affidavit or other special docs for students who took a drop)

List of documents required given below -

3 passport size photographs (the same as uploaded during registration)
Provisional JoSAA seat allotment letter
Photo identity card
Proof of seat acceptance fee payment
JEE Main 2017 Admit Card
Date of birth proof
JEE Main 2017 Score Card
Class XII Mark sheet
Category certificate (if applicable)

Fr further information, you can go through the below article -

JEE Main Counselling & Seat Allotment 2017

Hope this helps!!!