Why Harshit Rana is in Playing XI?

I am not a very strict follower of Indian Cricket or IPL, but I do watch important matches. Today when I saw the Playing XI, it got me curious why Harshit Rana is in playing XI. Do we not have any good bowlers?

Shami is just back from Injury. Kuldeep is one fulltime spinner, Three allrounders and then Harshit Rana. This seems like such a weak bowling line.

Why do we not include Arshdeep Singh or are we just keeping him for short formats?

Why Harshit is on the team? What's his specialty? Does he bowl extremely fast or swings quite well? His bowling seemed very above average, he would always be targeted whenever any batter would look to score fast runs. I guess he was with KKR, but why was he picked compared to any other bowlers in IPL or domestic format