Hello,

It would to be difficult to predict the exact score because the marks vs rank trend changes every year as the maximum marks to JEE Advanced changes every year. The cut off rank in JoSAA 2020 round 6 for admission to IIT, Kanpur in Aerospace Engineering was 1968 for OBC-NCL category. Taking the cut off rank in to consideration you should try to score 50-55% of the total score in JEE Advanced. The rank corresponding to the score that you score may change depending on total number of candidates appeared, top score in the exam and normalized score. To check the cut off you can logon to JOSAA official website or you can use the link below

https://josaa.nic.in/Result/Result/currentorcr.aspx