Dear Aspirant,

If you lock the seat then you have to go and report at the center. However, if you choose to slide the seat then you don't have to go for reporting at the center. If you do not like the seat allotted to you then you could slide over and if you like the seat then lock it, report at the center and fill the next round for upgrade. If you get the update then the previous seat allotted to you will be canceled and the new seat will become your current seat and then if you chose to lock it then again you have to go to report at the respective college.

Hope this clears your doubt.

https://josaa.nic.in/webinfocms/Public/home.aspx

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

Thank You.