Dear Karthi,

Will you please tell me which exam's couselling process are you asking about, so that I can guide you in a better way! 

Basically, In any counselling process of every exam there are 3 rounds. Firstly , you fill the application form online and give a list of preferred colleges in right order. Now, after a week, you will be alloted a college based on your score and ranking( This is the first round).

If you are satisfied with the college alloted you can choose the freeze option or else you can go for float. Float basically means you wait for the next round and you can even change your order of preference of colleges.The results of 2nd round are out within next week. Here you can get the same college or even a different one. You can freeze this option and take admission in that college or even wait for the next round which goes the same way.

Hope this helps!

All the best!