Hey Nurul,

As per your query, your seat will not be retained if you go for National upgradation round. If you are alloted with a seat in good branch in 3rd round itself then no need to go for upgradation round. But if you are not satisfied with your branch then go for upgradation round. Many times students gets their previously alloted seats in upgradation round also. So no need to worry if you are not satisfied with your branch then definitely go for upgradation round.

Hope this helps.

All the best!!