1- Garena Free Fire:
Garena Free Fire (also known as Free Fire Battlegrounds or just Free Fire) is a mobile battle royale game, developed and published by Garena Studios. The game was released in 23 March 2018 for Android and iOS on 23 March 2017.As of May 2019, Free Fire had over 100 million registered users. As of November 2019, the game has over 450 million registered users and has grossed over $1 billion worldwide.
2- Call of Duty: Mobile:
It is a free-to-play first-person shooter game developed by TiMi Studios and published by Activision for Android and iOS. It was released on October 1, 2019. In its first month, the game had over 148 million downloads and generated nearly US$54 million in revenue, making it the largest mobile game launch in history.
We are not sure about that but we just assumed that on the basis of the number of installation. If you have a different opinion, let us know in the comment box which game will beat Pubg.