Hi,

It is after round 4 seat allotment that the alloted eat will be auto freezed and it is for those candidates who have selected the willingliness as FLOAT in previous rounds. This is as per the UPCET 2021 Counselling Information bronchure. So as you're in round 3, auto freeze won't happen, it will happen after round 4 if you select Float.

I hope this helps,

All the best.