Man I'm not enjoying this impact player rule, it's looks like a cheat code in modern cricket. 
The scorecard should've been stopped at the 130 mark at best but due to this new rule, teams are free to use an extra batter and get away with the humiliation of sorts. It's a good edition for IPL or entertainment per se because of TRP and brand value with a mix of innovation but in the long term it's going ruin to Indian cricket for sure unless T-20I also introduces the "Impact Player" rule, which won't happen. 
Yeah. I don't like this rule either since it gives batters an even bigger advantage over bowlers widening the gap drastically. It sucks, but it is what it is. Hope they don't add in the T20I format though later on.
The team needs to collect only 66 runs off 50 balls to win. It is not a difficult task. If the batsmen can survive at the crease, they will collect 66 runs very easily.
They are 3 down now, but I am still expecting RR to win comfortably since they have plenty of firepower remaining.