I have 3 of the 2260/2262 models set up currently. All three have 5L of Eheim Ehfi Mech (tubular shape) mechanical media in the bottom of the filter on top of the bottom (long leg down) green lattice screen.
I then use 2" thick Poret filter foam, cut to fit, in 10 PPI and 20 PPI. I may even have more than 2 layers in some of the filters.
Next is a single or double layer of Polyfil brand traditional batting to act as a fine media.
Finally is a zippered mesh lingerie bag with either Eheim Substrat Pro or Seachem Pond Matrix for the bio-media. Last is the top (short leg up) green lattice screen.
You can really use any media that you want as long as you follow the recommendation to put the mechanical media in the lower half of the filter and the bio-media in the upper half of the filter.
Fahad, did you also get the instruction manual with the filter?