I can help you with the last year overall ranks for CS and IT branch -

Computer Science -
GNDCD -  Min Rank -8510 (01)
                   Max Rank - 34316 (01)

GNGND - Min Rank - 7
                  Max Rank - 163

Information Technology -
GNDCD - Min Rank - 28682 (02)
                  Max Rank -43639 (02)

GNGND  - Min Rank - 168
                   Max Rank - 358


Hope this helps!!!