I have scored 61 marks in comedk exam and iam from Andhra Pradesh. and my rank will be below 20000......??

With a score of 61, your probable rank is between 20,100- 21,400. This is just your predicted rank based on previous year cut-offs. Although, predictors try to be as accurate as possible, this year's ranks may be different as it depends on a lot of factors like the difficult level of the paper, candidates who have appeared for COMEDK 2019, etc. So to know for sure if your rank will be below 20,000 you'll have to wait for the results.
All the best!