In this post I will help you out with few commands which you can use to find the bit size of your machine. Generally of you are having a 64 bit machine then you will be able to install packages of both 32-bit as well as 64-bit but the same is not applicable for 32-bit machines.
# uname -m
i686
# uname -m
x86_64
If you get i386, i586 and i686 in your reply than that signifies your machine is 32-bit but if you get x86_64 or ia64 then your machine will be 64-bit.
# getconf LONG_BIT
32
# getconf LONG_BIT
64
Here you will get an output of bit size either 32 or 64.
# getconf KERNEL_BITs
64
# getconf KERNEL_BITS
getconf: Invalid argument (KERNEL_BITS)
# find /stand/vmunix
/stand/vmunix: PA-RISC1.1 executable ->32 bit
# find /stand/vmunix
/stand/vmunix: ELF-64 executable object file - IA64 ->64 bit
Follow the below links for more tutorials