4 hours ago, Dhruv Rathi said:
because of it's new policy
It's not really a policy per se. The current OS doesn't contain the necessary compatibility shims to run legacy 32-bit apps.
4 hours ago, Dhruv Rathi said:
Can anyone please help/guide me on how can I convert my 32 bit games to 64 bit
If you are lucky, and/or using an engine like Unity, you'll be able to just rebuild it for iOS 11 with the newest set of tools (i.e. new Unity, new XCode, and so forth).
If this is something your wrote in C/C++, then you may have to do a little porting work. But either way, fire up the project in the latest dev tools, set to iOS 11, and rebuild. The compiler should alert you to major 64-bit compatibility issues.