Hello Aspirant ,

Yes for admission in B. arch candidate has to go for counselling done by JosAA. It is done based on your JEE Mains paper 2 examination score and rank. 

It requires atleast 50% marks of 12th standard. 

It has rounds of counselling ,so you get sorted in terms of your ranks. The counselling will tentatively start from 3rd week of June 2019.

Hope this was useful. All the best.