Hello Nishita

Once the JEE Main April gets over The NTA will release the Ranks of the candidates and then JEE Advance will be conducted after the JEE Advance Result, You Need to register for JoSAA counselling which will be Free and then You need to fill the Choices as Per Your Preference So based On Your Category and Ranks You will be offered best possible choice To You.

Hope this Helps All the best.