Dear aspirant,

According to your question and taking into consideration that there is option to freeze your seat and it was the sliding round.

I would like to tell you that after the sliding round whichever branch you got ,this is the final allotment and you would take admission in this seat and that is the reason there is no freezing option.

If it is written in the information brochure to report to the college ,you have to report but i dont think the college would ask you to report physically ,it is surely online.