Hi , 

So congratulations for securing a good rank . In the 2018 entrance , a rank berweem 800 and 2400 would get an admission into the CS branch.  There is no official cut off as such for AU . They will call the selected candidates for counselling. It also depends on the number of candidates willing to join AU and those who cleared AUEET. So since you secured a good rank , you will definitely get a seat in au , civil quite easily . 

To know more , you can check this link 

Https://engineering.careers360.com/exams/aueet

For further queries do approach careers360.