You are Trying to install the Rstudio that is incompatible with your MAC so refer again to the CRAN and select the correct download for the ARM Architecture. If you still Persist the Issue I suggest you to use the web version of Rstudio that is Posit Cloud that has different versions of R installed choose among them as you need and it default provides about 1.5 GB of Execution memory enough to run medium memory intensive tasks.