Since "skachat mod liaz dlia omsi 2" means "download LiAZ mod for OMSI 2," you should look for the most popular Russian OMSI communities for high-quality models: : A major hub for Russian bus mods and maps.
Search for specific models like the (modern city bus) or LiAZ-677 (classic "Lunokhod"). skachat mod liaz dlia omsi 2
Click the download button and wait for the .zip or .7z archive to finish. Since "skachat mod liaz dlia omsi 2" means
Start OMSI 2 and load a map (like or a Russian map like Chistogorsk ). Click "Spawn a new bus." skachat mod liaz dlia omsi 2
: Move the Vehicles folder from the mod archive into your main OMSI 2 directory.