Exactly there are only two choices one is robi and the next is iyer. Rohit is more experienced than iyer but iyer did quite well in this IPL season. Knowing BCCI they will go for Rohit if required but if virat can perform as a captain in the upcoming T20 worldcup then I think they will stick with him.
I would rather prefer Shreyas Iyer over Rohit Sharma. Shreyas is 26 years old and he represents the future of the Indian cricket team. His captaincy was good during the initial phase of the IPL 2020, but later on he made some stupid decisions and received a lot of flak. On the other hand, Rohit Sharma is already 33 years old and he has only 3-4 years left in the international scene.