Hello

The seats in counselling are filled up in such a way that ,

If you don't get  preferred college in  second counselling for which you applied you will be left with old college which was alloted in round 1

In second round you need to put only good colleges for counselling ,it is because if you  you are unable to get into other good colleges you can continue with your old college which was alloted in round 1

If you get other good college in round 2 the fees which was paid for earlier college gets refund

Hope this helps you

All the best!