Probably you can modify it in the relative Config file inside the emulator folder.
As checked - no
Android emulator (version 30.0.5+) ignores hw.ramSize item in config.ini or the -memory option in the emulator command line. It's possible to adjust the memory size of AVDs at the qemu level. The command is like (at android-sdk/emulator/ folder) "emulator @avdName -qemu -m 1024"
emulator @10in_Tablet_Platform_30_google_apis -qemu -m 1024
This code starts the emulator with this setting of RAM, inside i was checking by HARDWARE-INFO app the needed RAM size is OK.
If to try 512MB RAM - it's very looong loading of emulator and not finished after 5 mins, interrupted.
768 MB was started OK for API level 30 (Android 11), very slow, but works.