Can we getting llvm win32 installer win64 installer be installed on same computer?
I don't object to this being possible, but it is probably work for someone and it's not clear what the benefit would be. The 32- and 64-bit builds of LLVM can both target 32- and 64-bit Windows (and Linux / macOS / *BSD / ...) so there should be no requirement to install both. If you can run the 64-bit version on your machine, it is likely to be a better choice.
While the 64-bit clang can also compile 32-bit executables, the
default triple for the 64-bit clang is 64-bit executables. For build
systems that assume gcc's cross-compile model (one compiler executable
per target platform), it might be helpful to use the 32-bits