I think Gill and Rohit will open for India. Dhawan doesn't deserve any more chance, Rahul is a good option but should start with Gill and Rohit.
Rohit is more or less certain and the only question is regarding the other opener. Shubman Gill should get the nod, although Kohli and Shastri are not in favor of dropping KL Rahul. Gill hasn't played T20Is recently, and his performance during the recent Test series against England was not up to the mark. Everything will depend on his performance for Kolkata Knight Riders in the IPL, which will start in around two weeks from now.
Left-Right combination is important so i think Kohli & co would prefer Shikhar over Gill and KL Rahul, at least for the 1st match. If Shikhar fails there then KL Rahul would get 2nd chance over Gill.