The story is a carbon copy of Vikram, but the director has tried to present it differently with Rajini.
The only difference is Viram was a multi-starrer and all the lead actors had almost equal screen-time and meaty roles. In Jailer, Mohanlal and Shivraj Kumar don't have much to do except walk about with cigars. Rajini himself has been reduced to look like a supporting character.
If you asked me, the hero of Jailer is Vinayakan. If not for him, the already flaccid role of Rajini would have been reduced to nothing.
As far as Rajini, he has tried very hard to bring his suave and swag, but you can see it's a 73-year old man trying to do what at 33-year old does. His age and his struggle to portray a youthful person is very evident in the flashback scenes as a jailer. Talking about that, I wonder why this movie was called Jailer when that part of his life was only featured for maybe 6 minutes.
Overall, Jailer is a slightly better offering than Annathae and Darbar, but definitely NOT a great show. I watched it in the cinema, but could have waited for the OTT release.