Ravali,

It is decided by counselling authoities to allot a seat to the candidate. And it depends on many factors such as rank obtained, marks secured and category. As you are from SC category, so you will be prefered over genral category candidates during seat allotment. As you are not alloted any seat in phase 1, this could possible that your rank was too much to get a seat in round 1. But don't worry, you will surely get a seat in the upcoming rounds.

Thankyou!