Hello Aspirant, 

As you've not mentioned the examination for which you want to fill the counselling form and by seeing your interest in engineering, I am telling you about the process for Jee Mains. 

First of all go to the official website of Josaa that is josaa.nic.in. There you will find a button for 2019 Josaa choice filling. Later you need to login with all valid credentials and you will be redirected to the page of choice filling.

Fill all the choices of branches and colleges in decreasing priority order or rearrange them in next step and then save all the process. 

On 25 June which is last date of registration, you will be allowed to use the button of choice locking, after which no amendments can be made in priority order.

There you go, your registration is completed and wait for first counselling list on 27 June.

Hope it helped you.!!