Hello aspirant, 

GAT results will be displayed on your screen when you hit the end button by popping up small window  

And GAT rank will be available after completing all slotes the wi give you a particular date for the announcement for rank. 

For more detailed information use below link 

Link:https://www.google.com/amp/s/engineering.careers360.com/articles/gitam-gat-result/amp

And then at last counseling process. 

Hope above information is helpful to you 

Thank you