See as you are an EWS student then the income aspects of your family is already satisfied. Now if we consider the salary range then also you are not eligible for any scholarship or economical weak student schemes. So essentially you may not need the certificate. But I would advise you to keep the certificate ready because there are always changes in regulations among the colleges. So if there are any issues then you will have to face the problems. So it would be better to keep it ready if required show it or else don't show. But if required and you didn't have the certificate then you may have to face problems.

To know more about JOSAA counselling visit the link below:

https://engineering.careers360.com/articles/josaa-counselling

I hope this answer helps. All the very best for your future endeavors!