After the installation, it ran first time smoothly with the GE-Proton9-26. But from the next attempts it showed the message "Game is not installed properly. Maybe try reinstalling". Tried to follow other contributors suggestions. Changed to Proton hotfix, Proton experimental etc. Also deleted and reinstalled the Rockstar social folders in the installed location (by verifying game files integrity). But nothing worked. Then from a forum I was directed to a github page, where it said to run the steam version of the game using GE-Proton9-27. Did that and voila! Game ran smoothly.

But there are still 2 problems,

1. Game cutscenes are very blurry
2. Online mode does not even launch due to the battleye issue.

If the game ran fine and you can make peace with these 2 issues, you will have a good time playing this game on linux.