Hello Neha,  after 1 St CAP round you have two options freeze and float. If you want to go for the next rounds then select the float option. By selecting this option you are accepting the offered seat and still eligible to go for the 2 nd round of CAP.  if you got the college you want in 2 nd round them you can select it and the acceptance in previous round will be cancelled automatically. And in case if you didn't get college then your previous choice will be continued. 

I hope it will help you more. 

Thanks.