Highrez

Is it possible to make a click of Ps2 with a mouse using InpOut32 ? How to do it ?

I don't know.
If you know the port addresses of the PS2 input buffer it may be possible - but why would you go to that effort when there are APIs in Windows like SendInput to send simulated input?

Frost or other protection system of MMORPG games is blocking Winapi.
There are applications that work with the Ps2 mouse directly. For example http://kibor-bot.com/stat/programmed-autoclicker.php
But I do not want to write bots through such applications, because it's inconvenient

That worked thanks, but how do you actually change the x and y coordinate of button?

You could try calling SetCursorPos() before clicking ??