i have not alloated the seats in first round of seat allotment then i have to gain fill the choice for next round or earlier choice filled will be considered for allotment.

Dear student,

Josaa will provide one time facility to students to fill choices in their preferred order and lock them before the deadline.
If any student doesn't lock his/her choices then after the deadline the choices will be locked automatically and then you can not change it any further, till last round counseling.

So, if you didn't get a seat in josaa first round counseling, then in or during second round counseling you can not change you preferred locked choices. These choices will remain same till last round. And if you think there might be a mistake in your choices then before locking up the choices then josaa conducts a mock seat allocation so that the students can know that whether they will get colleges based on their preferred order or not.
The mock seat allocation of josaa is on 12th October 2020, so if you have registered, then wait for mocl seat allocation and after that lock your choices by 15th October 2020. Because one you locked your choices then there is no chance that you can change any further or again fill the choices.

Also check out the following link to know more about josaa counselling :-
https://engineering.careers360.com/articles/josaa-counselling/amp

Hello,
There will be only one window for JOSAA counseling registration and choice filling. The registration and choice has already started for the year 2020 from October 6, 2020 and will be till 14 October.

Once  you fill your choice and lock your choices, you won't be needed to fill your choices again. Ther ewill be 6 rounds of seat allocation.

There will also be a CSAB spot round for the filling of the remaining seats.

Please visit this link for more information about JEE Mains JOSAA counseling 2020
Hope it helps