Hello Varalakshmi, congratulations on the selection!

And to answer your question, no you do not have to reapply for Tier II examination of SSC CGL 2021. You will only have to download the admit card once it has been released, generally around a week or two before the exam. You can subscribe to the alerts of any mainstream ed tech platform to make sure that you get instantly notified once the admit card link gets activated.

Best of luck!