This denotes the processor architecture. Modern Android devices (roughly post-2015) use 64-bit processors, which offer better performance and security compared to older 32-bit (armv7) devices.
Choosing an unofficial "repack" of Google Play Services exposes you to significant security risks. Because this app has deep system access, repacking it is a prime method for injecting malware. google play services 64bit arm nodpi android 90 repack