> So I should setup a cron job for the rsync?

Yes.

I suggest to standardize the location of input in RAS
installations, so we have the same place in a testing and a
production environment.

Let us create a directories

input/RePEc
input/CitEc

These could be symlinks, of course. I would do

input -> opt/input

so I should create /opt/input? or /home/aras/opt/input?

what is the current difference between /opt and /home/aras/opt?

on holda

So you would run

rsync -va adnetec@citec.repec.org:RePEc/zzz/cites/ ~/input/CitEc

> What time should it run?

Every day at about 15:00 local time to hit the evening in Valencia.