After our GATE we had no idea where to apply etc. There was this GATE Forum site which had a predictor which showed some data. That was useful but the sad thing is that that's all we have even after 7 years because no one wants to invest time for just 1000-2000 students. So, couple of years ago we tried collecting all the information regarding last ranks-- and this is in the below link. @Jothee is currenlty updating it. If you find any data (rank list PDF etc.) please add as a comment here to be updated on the page. Also, if you find the look bad and want to improve it you are welcome - its a google spreadsheet..
http://gatecselastrank.com/
Also we had this software by Pragy last year.
https://gateoverflow.in/mymarks/
Will see if it works for this years exam paper..
Last year mark and ranks
http://gatecse.in/gate-cse-2016-result-responses/
Where they joined?
http://gatecse.in/gate-cse-2016-admissions-responses/